Botanical Glossaries & Dictionaries

  Harris and Harris, Plant Identification Terminology.
A superb book with illustrations for every plant term.

Missouri Botanical Garden Botanical Research Glossary
Botanical Dictionary 

Pictured Interactive Biological Key

Dictionary of Botanical Epithets
Dictionary of Botanical Names 
Botanical Latin Pronunciation Guide

Abaxial: Away from the axis. The abaxial side of a leaf; the back side of a leaf. See dorsal.

Acaulescent: Stemless. See cauline.

Aceae: Group, family, as in Geraniaceae (the Geranium Family) and Liliaceae (the Lily Family).

Achene: A small, dry, fruit that does not split open, e.g., Sunflower seeds.

Actinomorphic: Having radial symmetry. Regular flowers, i.e., having all parts of the flower similar in size and arrangement on the receptacle so that if one were to cut the flower vertically in two anywhere, the two parts would be nearly identical appearing. See Hymenoxys hoopesii. Contrast with zygomorphic, irregular flowers.

Acuminate: Tapering to a sharp point from concave sides. "Acuminate" is commonly used to describe the shape of a leaf tip. See acute immediately below. Acuminate, acute

Acute: Tapering to a point from straight sides, as in an upside down V. "Acute" is commonly used to describe the shape of a leaf tip. See acuminate immediately above.

Adaxial: Toward the axis. The adaxial side of a leaf; the top side of a leaf.. See ventral.

Adnate: Attachment of unlike parts, e.g., fusion of stamens to the corolla. See connate.

Alpine: Above 11,500 feet (tree line).  Characterized by tundra: land of thin soil, rocks, a very short growing season, and frost any day of the year. Annually 30-55 inches of moisture, most from snow.  Magnificent carpets of dwarfed flowering plants in July and August.

Alternate: See leaf position.

Ament: See catkin.

Angustifolia: Narrow leaves, as in Populus angustifolia.

Annual: A plant which completes its entire life cycle of root, stem, leaf, flower, and seed in just one year and then dies. See Biennial and Perennial.

Anthesis: Botanical term for "flowering time", e.g., "The plant has no basal leaves at anthesis". 

Anthus: Greek for flower.

Apomictic:  Asexual reproduction.  Viable seed production without fertilization.  Taraxacum officinale (Dandelions) reproduce sexually or apomictically; Arnica cordifolia reproduces only apomictically.

Appressed: Pressed close or flat against another surface, as in hairs on a leaf or leaves appressed against a stem.

Areole: An organ, found only on Cactus, which gives rise to spines, flowers, stems, or roots.

Arvensis: Of the field, as in Cirsium arvense.

Ascending: Growing obliquely upward and usually curved. See appressed and spreading.

Banner: The topmost, relatively large, upright flower petal in many Fabaceae (Pea Family).  The "wings", which enclose the "keel", extend outward from the bottom of the banner.

Barbellate: Having minute prongs, as in the barbs on some Asteraceae pappus hairs.

Basal: See leaf position.

Basifixed: Attached only at their base, on their end, as in human hairs. Contrast with Malpighian.

Biennial: A plant which lives two years, producing a basal rosette of leaves the first year and a full plant, flower, and seed the second year followed by the death of the entire plant at the end of the second year. See Annual and Perennial.

Bisexual: Flowers having both stamens and pistils, also called "perfect flowers".

Bracts: Modified leaves that encase the flower bud and then subtend the flower after the flower opens. All of the bracts that subtend a flower are together called the "involucre".  (In Asteraceae, the floral bracts are called "phyllaries".)  See Arnica mollis. The term "bract" is also used to refer to very small leaf-like growths in Asteraceae.

Bundled: See leaf position.

Caespitose: Growing in a dense, low form. Sometimes used interchangeably with "tuft", "clump", "mat", "pulvinate". Some floras make a very fine distinction among these terms. "Mat", for instance, can be construed as only applying to "tightly spreading along the ground".

Campanulate: Bell-shaped.

Calyx: The outer segment of a flower that encases and then surrounds the petals.  The individual parts of the calyx are called sepals.  

Canescent: Incana. Coated so extensively with hairs as to have a gray/white cast.

Canyons: Deep and long depressions with walls of cliffs and slopes.  Pinyon Pine, Juniper, Sagebrush are common.  The Four Corners area is rich in deep, long, and beautiful red and white sandstone rock canyons.

Capitate: Head-like.

Carpel: A flower's female reproductive organ, consisting of the stigma, style, and ovary and made of an inrolled leaf. The peapod is an example. Many flowers have more than one carpel and the carpels collectively are called the gynoecium. See pistillate, stamen, staminate.

Catkin: A type of inflorescence consisting of an often pendulous dense collection of unisexual flowers that have no petals. Also called an ament. See the whole page of Ostrya knowltonii. Strangely, although all definitions of catkin and ament indicate that they are a collection of flowers, and no definition of catkin refers to seeds, the terms are also used to describe the seed chains. Thus we have a very common seed chain that has no name.

Caudex: The woody stem base of some herbaceous perennials. Although some floras indicate that caudices are below ground, others indicate they may be below or above ground. See Boechera.

Cauline:  On or pertaining to the stem, "cauline leaves".  "Acaulescent" means, therefore, "without a stem", as in plants which have leaves arising directly from the base of the plant at ground level but the plant has no stem. There are, however, almost always flower stems, "scapes". For acaulescent, see Micranthes.

Chaff: In Asteraceae (the Sunflower Family), a minute bract/scale-like, thin, dry plant structure sometimes present at the base of each floret (tiny flower). Chaff is attached to the receptacle. The presence, shape, and size of the chaff helps you determine the genus of some Asteraceae.

Chartaceous: Papery, as in some sepals. See Symphyotrichum ericoides.

Ciliate: Fringed on the margins with hairs.  The presence or absence of these hairs is sometimes important in distinguishing among species.  Usually the cilia can best be seen with a 10x hand lens. See Monardella odoratissima and Asters.

Cladistics: A widely accepted recent phylogenetic method for classifying plants.  Cladistics makes assumptions about the primitiveness of a group of plants' characteristics and represents these in a branching diagram (a cladogram).  Other cladograms are drawn based on other assumptions about primitiveness of characteristics.  Through the process of: "if this, then this, but not that" and by working with probability theories, it is believed that cladistics will lead to an understanding of which characteristics are most primitive and which evolved.  It is believed that cladistics will produce a more accurate classification of plants.  Click to read more about cladistics: in the Utah Native Plant Society newsletter, on the Missouri Botanical Garden web site, and in Wikipedia.

Claw: The very narrowed base of some broad flower petals or sepals. See Fendlera rupicola.

cm: centimeter

Colorado Plateau: See Four Corners.

Common Name: A name given to a plant by anyone in any language for any reason. See Plant Names for a discussion of why we should use scientific, not common names, how scientific names are arrived at, a brief history of the development of scientific names, why scientific names change, etc.  Very interesting.

Compound leaf: A leaf which is separated into two or more distinct leaflets. See Acer negundo. Also see leaf type.

Connate: With similar parts united, e.g., petals fused into a tube. See adnate.

Cordate: Heart-shaped.

Corolla: The name for all the petals of a flower taken together.

Corymb: A type of spreading, racemose inflorescence (often flat-topped, sometimes rounded) in which each flower stem ("pedicel") originates from a different point on the main flower stem. Lower pedicels are longer than upper ones thus producing a flat-topped cluster. Umbels, another type of inflorescence, have pedicels which originate from the same point, as umbrella spokes do, so pedicels are of equal length. See Google Images  and  Heracleum maximum.

Crenate:  With rounded marginal teeth.

Cuneate: Wedge-shaped.

Cyme: An inflorescence in which flower stalks emerge from a single point (as do those in an umbel). Pedicels of a single flower alternate with peduncles of several flowers. Terminal flowers bloom first.  In "racemes" the first blooming flowers are at the bottom of the flower stalk. Click for cyme drawings.

Deciduous: Shedding leaves annually. Used to describe a plant (usually a tree) which sheds all of its leaves each year in the fall.

Decumbent: Reclining on the ground but with ascending tips.

d: Decimeter. 10 centimeters. About 4 inches.

Decurrent: Leaf bases which grow down (wrap at least partially around) the stem. Cirsium parryi.

Deflexed: Bent abruptly downward.

Dehiscent: Splitting open at maturity.

Dentate: Toothed along the margin with the teeth pointing outward.

Depauperate: Significantly reduced in size or function.

Descriptions, botanical: A new plant's name and characteristics must be formally published for the plant's identity to be accepted by science.  This description must also be accompanied by a specimen of the plant deposited in a herbarium for others to view. 

The formal, detailed write-up of a plant's characteristics follows an accepted pattern of analysis and descriptive format. The plant's presently accepted name and the botanist who named it come first followed by the name of the person describing the plant (if different from the person naming the plant). These are followed by past names ("synonyms"); perhaps a common name; a generalized overview of the plant including whether it is perennial, annual, etc.; then the details of the plant's morphology starting with the roots, stems, and leaves, then the flower in considerable detail, then the fruit, chromosomes, and finally notes on habitat, similar species, other botanist's agreements/disagreements with the descriptive notes, etc. 

Similar species are referred to and the plants position in a botanical key may be included.  Details about the plants location, range, unusual characteristics, etc. are included.  An abstract both in the native language and Latin are included. (As of 2012, a Latin description is no longer a requirement.) 

A plant may inadvertently be described more than once by different botanists.  Each description may result in a different scientific name until someone examines all the specimens and determines which are the same species and which name takes precedence, the latter according to the "International Code of Botanical Nomenclature".   See Scientific Names and Plant Names and click to read the description of a plant Betty and I discovered.

Determinate: Describing an inflorescence in which the terminal bud opens first thus halting any further elongation of the main flowering axis. Contrast with indeterminate.

Dioecious: (Pronounced, die e cious) A dioecious species bears its male (staminate) flowers on one plant and female (carpellate) flowers on another. The Greek "dioecious" means "two houses".  See monoecious

Disjunct: Occurring in widely separated areas, as in disjunct plant populations.

Disk or disc (and ray) flowers: What we perceive as a single flower in Asteraceae (the Sunflower Family) is actually a flower head composed of a myriad of tiny disk and/or ray flowers. 

Asteraceae flower heads can be composed of two different flower types:

1) Disk flowers are numerous and packed tightly. Each disk flower is very small, thin, vertical, and tubular, almost always with 5 tiny lobes.

2) Ray flowers either are few and surround the disk flowers in one circular row or are numerous (and there are, then, no disk flowers). Ray flowers are very small, thin, vertical, and tubular, with one elongated (quite short to long), strap-like petal. 

Some Asteraceae species are composed only of disk flowers (thistles, for instance); some Asteraceae are composed only of ray flowers (dandelions, for instance); and many are composed of both disk and ray flowers (the large sunflowers along roadsides, for instance).

Asteraceae disk flowers are usually bisexual and fertile, each producing one seed, but some Asteraceae species have disk flowers that only have stamens and they are thus sterile, i.e., they do not produce seed.

Most species of Asteraceae ray flowers are often pistillate, i.e., they have only styles and produce one seed, but in some Asteraceae species, ray flowers may be bisexual, sterile, or contain no sexual parts.

See Arnica mollis   Oxytenia acerosa   Ohio plants, Asteraceae.

Distal: Toward the tip, opposite the point of attachment. See proximal.

Disturbed Areas: Roadsides, mined areas, grazed lands, timbered lands, and ski slopes are unnatural disturbed areas.  There are also natural disturbed areas: snow and rock avalanche areas; ground burrowings from gophers, prairie dogs, etc.; Elk wallows, animal tracks, and animal foraging.

Divaricate: Extremely divergent.

Divergent: Spreading away from the main axis of growth.

Dolabriform Hairs: See Malpighian Hairs.

Dorsal: The back or outward surface, as in the lower surface of a leaf. Also abaxial. See ventral.

Drought:  Precipitation in the Four Corners area averages from 6 to 15 inches per year in the elevations of 5,000 to 7,000 feet and increases dramatically up to the high montane areas that receive around 300 inches of snow per year and another 20 inches of rain. 

But precipitation is highly erratic; few months or years are average and, in fact, some months or even years are considerably wetter or drier than average.  The "average" precipitation is, therefore, not the "usual" precipitation.

Plants of the Southwest are comfortable with these variations; they have evolved in and continue to thrive in these erratic conditions.  Human beings are not comfortable with varying precipitation levels; they want a consistent water supply for boating on their reservoirs and watering their lawns and golf courses.

Drought is made harsher for human beings by three factors: hard freezes in June, high winds, and above normal temperatures which evaporate snow from the mountains and water from reservoirs.  Less snow means less water in the rivers, which means less water in the river-fed reservoirs. There will then be less irrigation water, fewer crops to feed the cattle, less cattle money for purchases at local businesses, less tax money collected and thus less money for road repairs, schools, health care, golf courses. 

We have tried to build a watered way of life for too many people in the erratically dry Southwest.

Wild animals, too, can be caught in a negative chain of events: a freeze in June means that many Oaks will have their leaves and flowers frozen.  The acorn crop, which many wild creatures depend on, will be sharply reduced. But Oaks put out a second set of leaves and those creatures which eat acorns also eat other wild foods. 

What are the results of drought for wildflowers?  The number and size of plants and flowers will be greatly reduced. Flowers, and sometimes even plants, will be confined to little rivulets of water across meadows, in seeps, etc.  Low desert areas may have very few flowers.  Plants will bloom weeks early or late. There will be no flowers for some species and few flowers for most species. Flowers will last a short time. Those plants that do flower will produce seeds that have a better chance of surviving dry conditions.  Evolution continues.

E: Without, as in ebractate, eglandular.

Endemic: Found only in a small region, in a particular ecological niche. "Ipomopsis ramosa is endemic to Dolores County, Colorado."

Entire: Not toothed, notched, lobed, or divided. Especially pertaining to leaves. See leaf blade margin.

Epigynous: Inferior, as in an inferior ovary where the floral parts are attached to the top of the ovary.

Erose: With margins irregularly toothed, seemingly gnawed.

Evergreen: A plant which retains a large portion of its green leaves all year. Evergreen plants do, however, drop leaves at various yearly intervals. Often all leaves are retained for the first 3-8 years of growth on the new stems. Then the earliest growth of leaves yellow and drop.

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Falcate: Sickle-shaped. Shaped like the beak of a falcon.

Family: A large grouping of plants with shared characteristics.  Often these characteristics are visually apparent to the unaided eye: the green, slender, long and narrow-leaved upright structure of grasses; the wide, flattened disc usually fringed by numerous, long, thin petals flared outwards of the Sunflowers; the cross-shaped four-petaled flowers of the Mustards; the umbrella-like flower structure of the Parsleys; the long thin needle leaves of Conifers.

Learning such key characteristics of just 19 families will, as William Weber points out in his Colorado Flora: Western Slope, assist in identifying over 75% of the plants in the Four Corners region (and in most other areas). The Western slope of the Colorado Rockies has over 2,100 species in 139 families; Weber indicates that almost 1600 species are in 19 families. 

Knowing characteristics of just six families will open the door to almost half the plants. The top six families are: Asteraceae (Sunflower) with 354 species, Poaceae (Grasses) 208, Fabaceae (Pea) 138, Cyperaceae (Sedges) 123, Brassicaceae (Mustards) 119, and Scrophulariaceae (Snapdragon) 99. 

See Genus, Species, Scientific Name, and Plant Names. Scientific names shown in bold on the enlarged photo pages are the currently accepted names according to John Kartesz's Synthesis of the North American Flora.  Scientific names shown in normal font are synonyms.

Farinose: Covered with a mealy, powdery substance.

Fascicle: A bundle or cluster as in "a fascicle of stems" or "the flowers are in a fascicle". See Orobanche fasciculata.

Floret: A small flower, as in the small flowers that make up an Asteraceae flower head.

Flower: The reproductive portion of some plants, consisting of either pistils or stamens (imperfect flowers) or both (perfect flowers) and usually including sepals and petals. 

Because a plant has flowers it does not necessarily follow that the plant reproduces itself exclusively by the ripened ovary of this flower.  Some plants propagate more from underground root spread (Vaccinium myrtillus) or from above ground stolons (Fragaria) or from plant parts that fall to the ground or are carried to new ground by animals and then root (Opuntia).  And plants such as ferns do not flower at all, but they instead have spores, reproductive cells that can give rise to a new plant.

Some plants have a very short flowering period, others bloom the entire summer.  Some plants put out a single flower, others have numerous flowers, either over a long period of time or within a few days.  Some individual flowers last part of a day; others for many days.  Some flowers open early in the day, some in the heat of the day, others at night. Some flowers open and close a number of times; some flowers remain open until they wither. 

Foothills: From 6,500 to 8,000 feet. Pinyon Pine, Juniper, and Oak forests, often quite thick. Pockets of Douglas Firs.  Ponderosa Pine at higher elevations.  Numerous shrubs: Serviceberry, Mountain Mahogany, Snowberry. Annually about 14-25 inches of moisture, about half from snow. Moderate wildflower growth in May and June.

Forb: Herbaceous plants other than grasses.

Four Corners:  The area covered in this web site extends in a hundred and fifty mile radius from the Four Corners, the meeting point of the borders of Colorado, New Mexico, Arizona, and Utah.  The area covered is bounded on the east by the Continental Divide at Wolf Creek Pass just east of Pagosa Springs, Colorado; on the southeast by the Ojito Wilderness Area north of Albuquerque, New Mexico; on the southwest by Petrified Forest National Park, Arizona; on the northwest by Grand Staircase/Escalante National Monument, Utah; and on the north by Arches and Black Canyon of the Gunnison National Parks.  The Four Corners area is part of the larger Colorado Plateau: the mountains, mesas, canyons, and semi-desert lands which are drained by the middle section of the Colorado River.

Fruit: A ripened ovary.

Fusiform: Spindle-shaped, i.e., broadest in the middle and tapering at both ends. Mertensia fusiformis.

Galea: Hood-like upper lip of some two-lipped corollas. See Pedicularis.

Gall:  An abnormal bulbous formation on plant leaves or stems.  Galls result from a plant's attempt to protect itself from an unusual occurrence, usually a mass of insect eggs deposited on its surface.  Plant cells multiply rapidly to isolate the foreign substance, but this at the same time provides shelter for the substance.  The plant suffers little damage from the insects or the gall.  Picture of gall.

Genus: A subdivision of the Family in which all members have a significant number of similar (or identical) characteristics.  With practice an amateur can often determine the genus without recourse to detailed botanical texts and a magnifying glass.  The genus name is capitalized and accompanied by and followed by the specific name; both are italicized, for example, Rosa woodsiiRosa is the genus and woodsii is the specific name (also called the specific epithet).

Scientific names shown in bold on the enlarged photo pages of this web site are the currently accepted names according to John Kartesz's Synthesis of the North American Flora.  Scientific names shown in normal font are synonyms. See Family, Species, Scientific name, and especially Plant Names.

Glabrous: Smooth, without hairs. Whether a twig, stem, or leaf is glabrous or pubescent often is important in distinguishing between species, but the amount of hairiness often varies with the age of the plant. See pubescent.

Gland: A protuberance, often a hair-like structure, that secretes sticky or oily substances which often impart a stickiness and an odor (often pleasant) to the plant.

Glandular: Having glands, sticky. "Glandular" is often used to describe plant hairs which are ball-tipped with glandularity imparting a stickiness to the plant which is observable because dirt sticks to the plant, because the plant feels sticky, and because there is often a smell (commonly very pleasant) associated with the glandularity. Penstemon breviculus.

Glaucous: With a whitish, often waxy, coating. Pruinose. Streptanthus cordatus.

Glochids: Tiny barbed hairs which grow from areoles of cacti. Opuntia phaeacantha.

Glomerate: Crowded into a compact, spherical mass. Ball-like. Cymopterus glomeratus.

Gracilis: Slender.

Grandiflora: Large-flowered.

Gynoecium: Collective name for all the carpels in a single flower.

Habitat: As used in this web site, "habitat" refers to the environmental components (rocks, wetlands, woodlands, etc.) in which a plant best survives.

Herb or herbaceous: A plant whose stems die back to the ground in the winter. See Woody.

Hirsute: With stiff, coarse hairs

Hypanthium: The swollen cup-like structure formed by the fused bases of the stamens, petals, and sepals. See Lithophragma tenellum.

Hypogynous: With floral parts attached below the ovary. A superior ovary. Arnica mollis.

Imbricate: Shingled, overlapping as in many Asteraceae phyllaries. See Xanthisma grindelioides.

Imperfect flowers: Unisexual. Flowers with only stamens or only pistils, but not both. Contrast with perfect and bisexual.

Incana: Coated so extensively with hairs as to have a gray/white cast. Also, canescent.

Indeterminate: Describing an inflorescence in which the lower buds open first thus allowing continued elongation of the main flowering axis. Contrast with determinate.

Inferior: Epigynous. Attached below. Commonly used to describe the position of a flower's ovary in relation to the point of attachment of the petals and sepals. Contrast with superior. Epilobium.

Inflorescence: A flower cluster. The main types of inflorescences are spikes, racemes, panicles, corymbs, umbels, and cymes.

Involucre. involucel: The cluster of bracts that subtends a flower. See, for instance, Lonicera involucrata. An involucel is smaller than the involucre of that same plant. See Vesper. Asteraceae bracts are usually called "phyllaries".

Involute: With margins rolled upward and inward onto the upper side of a leaf. See revolute.

Irregular Flowers: Zygomorphic. Asymmetrical flowers. Such flowers can be divided only one way to produce mirror images. The parts of the flower are dissimilar in size or shape and are not arranged symmetrically on the receptacle so that if one were to make a vertical cut dividing the flower, the two halves would not, except in only one place, one cut, look alikeCalypso bulbosa. Contrast with regular flower, actinomorphic.

Keying a Plant: The process of identifying a plant with a botanical text. Most professional, detailed, accurate keys are "dichotomous", i.e., you are presented with two either/or questions about plants. You select one and that moves you on to another two questions. Eventually you have only one choice: the plant you are trying to identify. Simple sounding. Difficult, time-consuming, and rewarding in practice. See Scorzonera laciniata for an example of the difficulties in keying. Click to learn about how to use a botanical key.

Laciniate: Cut into into narrow, irregular lobes or segments. Scorzonera laciniata.

Laevigate: Lustrous, shiny.

Lanate: Woolly. Used in describing the hairs on a plant. See the similar terms: villous and tomentose.

Latiflora: Wide flowers.

Latifolia: Wide leaves.

Leaf position: Leaves can grow from opposite sides of a stem; or leaves can grow on one side of a stem and then on the other side at a higher level, i.e., alternate; or leaves can grow in tufts at the base of the stem; or leaves can grow in whorls around a single area on the stem; or leaves can spiral around a stem; or leaves can grow in bundles from the same point on a stem.

A species can have leaves growing in several of the above positions, e.g., many plants have basal leaves and they also have leaves on the stem. Some plants have no stem leaves. Some have no basal leaves. Some plants have both opposite and alternate leaves.

Many plants have leaves in certain positions, say basal, early in the season, but these leaves wither and disappear as the plant ages. Keys for identifying species almost always give characteristics at full maturity of the flowers, and one identifying characteristic you might be asked about in a key is whether and where there are leaves at flowering time (anthesis).

The leaf position is one of several leaf characteristics helpful in identifying a species. Click to see leaf position photographs.

Leaf blade margin: Margins of leaves can be entire, i.e., have smooth edges that are not at all toothed, lobed, or divided,  or the margins can be irregular, i.e., they might be toothed, serrated, lobed gently, cut shallowly or deeply, etc.

The leaf margin is one of several leaf characteristics helpful in identifying a species. Click to see leaf blade margin photographs.

Leaf blade shape: From species to species, leaf shape varies enormously in length, width, and proportions, and there are numerous terms to describe these various leaf shapes: lanceolate, oblanceolate, ovoid, obovoid, linear, spatulate, oblong, cordate, orbicular, etc.

The shape of a leaf blade is one of several leaf characteristics helpful in identifying a species. Click to see leaf blade shape photographs.

Leaf type: Leaves are either simple, i.e., the leaf blade is not divided into separate leaflets., or leaves are compound, i.e., the leaf blade is divided into separate leaflets. Simple leaves might have smooth margins, toothed margins, lobed margins, etc., but the indentations in the leaf never reach all the way to the center vein (the rachis). Compound leaves might have leaflets with smooth margins, toothed margins, lobed margins, etc. The small leaflets might be cut again to their rachis thus producing smaller and smaller leaflets.

The leaf type is one of several leaf characteristics helpful in identifying a species. Click to see leaf type photographs.

Lentiginous: Scurfy, covered with small scales.

Leucanthus: White-flowered.

Limb: The expanded end of a tubular corolla. See throat and tube.

Lobe: A protruding, usually rounded, division of an organ, such as, the wavy, indented edges of some oaks and the tips of many tubular flowers Penstemons. See sinus.

Locules: Cells or chambers, as in the cells of an ovary.

Lutea: Yellow.

Malpighian Hairs: Hairs which lie flat against the plant surface but are not attached to the surface at the end of the hair.  Instead they are attached somewhere along the length of the hair (often toward the middle) by a very minute projection of the hair.  Both ends of the hair taper to a point and the hair is thus a squat T-shape, similar to a pick-axe head. Also called "dolabriform hairs". See Astragalus ceramicus.

m: meter

Marcescent: Withered but persistent, as in some basal leaves.

Meadows: Large grass and wildflower filled areas with few, if any, trees.

mm: millimeter

Monocarpic: A monocarpic plant is one which grows for a number of years until it flowers for the first and only time, fruits, and dies.  The Century Plant is monocarpic.  See Frasera speciosa and Eriogonum alatum for examples of two fascinating monocarpic plants in the Four Corners. 

Monoecious: (Pronounced, mo knee cious) A monoecious species bears its male (staminate) flowers and its female (carpellate) flowers on the same plant and thus all plants can bear fruit. The Greek "monoecious" means "one house". See dioecious.

Montane: In the Four Corners area, 8,000 to 10,000 feet.  Open Aspen forests, sometimes with heavy undergrowth of shrubs (Snowberry, Currants, Elderberry). Colorado Blue Spruce in moist areas.  At lower elevations some large stands of Ponderosa Pine with scattered Douglas Fir on north facing slopes. Annually about 18-30 inches of moisture 1/2 to 3/4 from snow. Moderate to lush wildflower growth from June-August.

Mucronate: Tipped with a short, sharp, abrupt point as in some leaves.

Nerves: Used most often to refer to the veins of leaves. Helianthella quinquenervis.

Node: The point at which there is an attached growth, as in the place where each leaf is attached.

Noxious Weed: Often this term is used in a very specific legal manner to describe a plant which has been introduced to a location, is a non-native plant, and which often crowds out native species or species of economic value.  See the full page discussion of the noxious weed problem.

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Ob: Inverted. An oblanceolate leaf has the inverted shape of a lanceolate leaf, i.e., it has its narrowest part at the point of attachment and then the leaf gradually widens.

Ochroleucous: Yellow/white.

Officinale: A Latin term meaning "a shop" or "carried in a shop". Botanically, "officinale" came to mean, "a plant carried in an office, i.e., an apothecary shop".  Taraxacum officinale, Cynoglossum officinale

Oides: Similar to, as in Populus deltoides, similar to the shape of a delta or Chaetopappa ericoides, similar to Ericaceae, heathers.

Openings: Small rock or meadow clearings in woods.

Opposite: See leaf position.

Panicle: A type of inflorescence in which branched flower stalks are attached to the main flower stem, i.e., a panicle is a branched raceme. The bottom flowers in a panicle open first. See thyrse.

Pappus: Small scales, bristles, or, very often, silvery hairs at the apex of the seed in Asteraceae species.  The texture, number, and shape of the pappus are key in distinguishing between Asteraceae genera and species. See Heterotheca zionensis for a close-up of inner and outer pappus hairs. Also see Arnica mollis

See Scorzonera laciniata for a discussion of the confusing definition given to pappus hairs and pappus scales by the Flora of North America.  

See the Arnica page for photos of pappus and also see Taraxacum officinale and Senecio spartioides for a view of pappus hairs that we all know.

Parasitic: A plant that lives off the live tissue of other plants and fungi. See saprophytic.

Parviflorum: Small-flowered.

Pauciflorus: Few-flowered.

Pedicel: The stem of a single flower. If a flower has no stem it is said to be "sessile".  See "peduncle" immediately below.

Peduncle: The common stalk of a cluster of flowers.  See "Pedicel".

Perfect flowers: Flowers with both male and female parts; bisexual.

Perennial: A plant that lives and blooms for many yearsSee Annual and Biennial.

Perfoliate: Describing a leaf which completely surrounds the stem to which it is attached.

Perianth: The calyx and corolla of a flower taken collectively.

:Petiole: The stem of a leaf. "Petiolate" means, "with a petiole".

Phila: Loving.

Phyllaries: The modified leaves that cover and then subtend flower heads in Asteraceae. Also called "bracts". All of the phyllaries/bracts that subtend a flower are together called the "involucre". Photographs of phyllaries: Grindellia, Dieteria, Aster, Arnica mollis.

Phylogenetics: The system of plant classification that tries to reflect evolution.  Phylogenetics arose after Darwin at the beginning of the 20th century and is still evolving as it searches for a basis for ordering plants in their evolutionary sequence. Early phylogenetic systems started with basic assumptions about which features of plants were most primitive and which were derived, evolved characteristics.  Recent classification tries to base the ordering of plants on scientifically verifiable, rather than on subjective, assumptions about primitive versus evolved traits.  See cladistics.

Pilose: Bearing long, soft, straight hairs. This is one of many terms describing the shape and texture of plant hairs.

Pinnate, pinnatifid, pinnatisect: The Latin "pinna" means "feathered". The term is used to describe leaves that have a primary central midrib from which leaf subdivisions branch, i.e., the leaf is cut into a number of subdivisions called leaflets or "pinna". Each of these pinna might be cut again into divisions and these divisions can again be cut. Click to see. And click again.

There are various terms to describe how deep the cut is in the leaf or leaflet and whether the individual segments have a stem. Most botanists agree with the following:

If the leaf is cut about half way to the midrib (but not to the midrib), the leaf is said to be "pinnatifid".

If the leaf is cut to the midrib, it is said to be "pinnatisect".

Many plants have pinnate leaves: Ferns, Mimosas, Ashes, Peas.

Pistillate: Containing only carpels, only female floral parts. See staminate, carpellate.

Plumose: Feathery, i.e., having hairs or fine bristle on both sides of the main axis. Often used in describing the shape of pappus hairs. Arnica mollis.

Proximal: At the base. The lower end near the point of attachment. See distal.

Pruinose: Glaucous. With a white waxy or dusty coating.

Puberulent: Minutely pubescent with fine, short hairs.

Pubescent: Hairy. Pubescence is a distinguishing factor in plant identification.  Pubescence may vary from leaf to twig to stem and with the age of the plant. Pubescent sometimes means, "with short, soft hairs". See glabrous.

Pulvinate: One of a number of terms used to describe a cushion-like or mat-like growth habit. Similar to tuft, caespitose, mat, etc. Physaria pulvinata.

Pumila: Dwarf, small.

Pustulose: With small blisters (pustules) at the base of a hair.

Raceme: An elongated type of inflorescence with individual flowers attached to a central stalk by a flower stem (a pedicel).  See Actaea rubra for an example of a raceme. A raceme flower arrangement also can refer to the general habit of flowers blooming first at the bottom of the stalk.  Racemes, spikes, umbels, and corymbs flower from the bottom up.  Cyme flower arrangements bloom first at the top of the stalk.

Rachis: A main axis, such as that of a compound leaf.  The stem to which each leaflet is attached.  Click to see the red rachis of Asplenium trichomanes.

Ramos: Branched. Ipomopsis ramosa.

Rare: The term "rare" is used by most lay people to mean "unusual" or "not seen very often", but it has a more precise scientific meaning. The New Mexico Rare Plant Technical Council defines it as follows:

A taxon that is narrowly endemic to a specific geographic feature (e.g., mountain range; geologic outcrop) or subset area of a phytogeographic region (e.g., southern Rocky Mountains, northern Chihuahuan desert). It can be locally abundant within its narrow range, but typically will not extend more than 100 miles in length of range; OR A taxon that is more widespread, but is numerically rare - never locally common - throughout its range or is numerically abundant only in a few small, widely scattered habitats.

See the Colorado Rare Plant Guide for further information. Also see the federal definitions.

Ray Flowers: See Disk Flowers.

Receptacle: The uppermost portion of the flower pedicel or peduncle to which the floral parts are attached. Especially in keying Asteraceae, one is sometimes asked about the structure of the receptacle. See the second from the top photograph at Brickellia oblongifolia. Also see "chaff".

Regular Flowers: Actinomorphic. Symmetrical flowers. All parts of the flower are similar in size and arrangement on the receptacle so that if one were to cut the flower vertically in two anywhere, the two parts would be nearly identical appearing. See Hymenoxys hoopesii. Contrast with irregular flowers. 

Recurved: Curved backward. See the last photograph at Grindelia squarrosa.

Reniform: Kidney-shaped.

Reticulate: A network of veins. Net-veined. Salix nivalis.

Retrorse: Directed backward or downward. Revolute. Eriogonum leptophyllum.

Revolute: Retrorse. With margins rolled backward and under onto the lower side of a leaf. Often used to describe the edge of a leaf. See involute.

Rhizomatous:  Arising from horizontal underground root-like structures (rhizomes) that sprout new plants from their nodes. Erigeron ursinus.

Rocks: Areas of large rock in canyons or mountains.

Rosette: Usually used to describe a dense cluster of leaves at the base of a plant. Eriogonum alatum.

Rostrum: A beak-like structure.

Ruderal: Growing in disturbed habitats. Weedy.

Runcinate: Saw-toothed or sharply incised with retrose teeth, i.e., with teeth pointing backward or downward.


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Samara: A winged seed such as found in Box Elders, various other Maples, Elms, etc.

Saprophytic: An obsolete term that mistakenly meant, "a plant that lives off dead organic material".  No plants live off dead organic material; only fungi do that.  It is now known that plants described as saprophytes are actually parasites living off fungi.  The mycorrhizal fungi transfer nutrients from the host plant to the parasite. The fungi are parasitic on various plants. 

Plants formerly considered saprophytes are now considered parasites and they are called "myco-heterophytes" or "myco-heterotrophs". See parasitic.

Scabrous: Rough to the touch due to the plant's upper cell structure and/or to the presence of short, stiff hairs.

Scape: A leafless peduncle arising from the ground level in acaulescent plants, i.e., a leafless stem of a flower cluster. The flower stem arises from the ground. See Micranthes oregana and Micranthes rhomboidea.

Scarious: Thin, dry, and membranous in texture, not green. Used in describing the texture/color of some phyllaries. Cirsium scariosum and Vesper spp.

Scientific Name: A two part Latinized name assigned by botanists to plants and accepted internationally. Examples: Ipomopsis ramosa, Linum lewisii, Iris missouriensis, Populus deltoides. The two words (the genus and the specific epithet) describe a plant's characteristics, or honor a person, or commemorate a place, or describe a relationship between plants, etc. .

Scientific names shown in bold on this web site are the currently accepted names according to John Kartesz's Biota of North America Program.  Scientific names shown in normal font are synonyms.

See Plant Names for a discussion of why we should use scientific not common names, how scientific names are arrived at, a brief history of the development of scientific names, and why scientific names change.  Very interesting.  

Also see Genus, Species. Synonyms.

Scopulorum: Rocky places.

Scree: Fields (often extensive) of small (often one or two feet on a side and an inch to a foot thick), loose, slab rock.  Such loose rock fields are very common above 11,000 feet in the San Juans. Larger boulder fields are called "talus" but the two terms grade into each other.

Secund: One-sided, e.g., secund flowers either bend to or emanate from one side of the flower stem.  See Solidago velutina and Penstemon lentus.

Semi-deserts: From 5,000 to 6,500 feet.  Arid.  Annually 7-14 inches of moisture, 1/4 or less from snow.  Semi-desert areas are characterized by open, sandy flats with scattered shrubs (Saltbush, Sagebrush) and Cottonwoods along washes.  Higher semi-desert canyons have Pinyon Pine, Juniper, and Oak with some thick patches of Sagebrush, Yucca, Mountain Mahogany, and other shrubs.  Wildflower growth is best from March to June but is highly dependent on winter moisture.

Septum: A partition, e.g., the partitions in an ovary that separate the locules.

Sepals: Floral parts that enclose the petals and then surround them after the flower opens.  Taken collectively, the sepals are called the "calyx".  Sepals may have petals curved back through them; they may alternate with the petals: they may be smaller than or larger than the petals; etc.  See Mitella stauropetala and Ceanothus fendleri.  Sepals can be quite attractive and a key visual element of the flower, as they are in the Colorado state flower, Aquilegia coerulea (Columbine). Or the sepals may be inconspicuous. Or they and the petals may be indistinguishable and then termed "tepals".

Sericious: Silky, as in hairs.

Serrate: Saw-like; with forward pointing teeth along the margin, as in some leaves.

Sessile: Lacking a stem. Flowers and leaves can be attached to their main stalk with or without a stem.

Setose: Covered with bristles. "Setaceous" means bristle-like.

Shrublands: Arid lands characterized by shrubs, grasses, and a lack of trees.

Silicle: A fruit of Brassicaceae (the Mustard Family) which is typically less than twice as long as wide, often round and flat. See silique below.  Alyssum parviflorum.

Silique: A fruit of Brassicaceae (the Mustard Family) which is typically more than twice as long as wide. See silicle above.
Some floras dispense with the differentiation made between these two terms and call all Brassicaceae fruits, "siliques".  Descurainia spp  Boechera spp

Simple: The leaf blade is not divided into separate leaflets. See leaf type.

Sinus: A cleft, indentation between lobes, as in the indentations on an oak leaf.  Quercus gambelii.

Sori: The dots on the back of fertile Fern fronds.  These sori are actually groupings of many individual sporangia, each of which encloses numerous spores (the reproductive bodies of Ferns). Polystichum lonchitis.

Sp: Abbreviation for "species".  (Plural is "spp".) These abbreviations are most often used to indicate that the exact species is unknown, e.g., "Aster sp" would mean that the writer is confident the plant is in the Aster genus, but they do not know exactly which species it is.  Spp might be used to label the plants in a photograph when there are a number of different species of the same genus but they have not been individually identified.

Spatulate: Shaped like a spatula. Usually used in describing a leaf that is round at its tip and gradually tapering to its narrow base. Oblanceolate leaves are also wider at their tip but they are not round at their tip.  Boechera lemmonii.

Species: A single, individual, unique plant. A subdivision of the genus.  A species has enough unique characteristics that it can be differentiated from all other plants within the genus and from all other plants of any genus. 

It is generally true that one species cannot fertilize another species. Intermountain Flora indicates:  "A typical species is separated from other species by an absolute or nearly absolute gap in the variability, and by a complete or nearly complete barrier to interbreeding."

The scientific name for a plant, i.e., the name of the species, is two-part, two words.  The first word designates the genus to which the species belongs and the second word, called the "specific epithet" (or "species epithet"), gives a name to distinguish this plant from all others in the same genus.  For example, in the name Senecio serra, "Senecio" is the genus and "serra" is the specific epithet.  There are many other Senecios but only one Senecio serra  --  in the entire world.  

Both the genus and the specific epithet are italicized; the genus is capitalized and the specific epithet is lower case Senecio serra. 

Identifying the species is more complicated than identifying the family or genus and requires carefully examining the entire plant utilizing a magnifying glass and detailed botanical texts. 

Scientific names shown in bold on the enlarged photo pages of this web site are the names accepted by John Kartesz in his labor of 40 years, the Biota of North America Program. Scientific names shown in normal font are synonyms. See Family, Genus, Scientific Name, and Plant Names and synonyms.

Specific epithet: Scientific names consist of two parts, the genus name and the specific epithet. In the name, "Geranium richardsonii", "Geranium" is the genus and "richardsonii" is the specific epithet.  Frequently the specific epithet is incorrectly called the "species", i.e., it is incorrect to say that "richardsonii" is the "species".  The species is Geranium richardsonii.

Speciosus: Showy, as in, Erigeron speciosus.

Spike: An elongated type of inflorescence in which each flower is sessile, i.e., attached to the stem directly without itself having a stem (a "pedicel"). See Elephant Heads for an example of a spike.

Spiraled: See leaf position.

Sporangia: See "Sori".

Spores: See "Sori".

Sporophore: The fertile, spore-bearing portion of Botrychium.

Spreading: Diverging, extending horizontally, as in branches, petals, etc. See divergent. Contrast appressed and ascending.

Squarrose: Recurved.

Ssp:  Subspecies.  Also "Subsp".  Literally, "almost a species".  See "Var".

Stamen: The pollen producing part of the flower. See carpel.

Staminate: Having only male, pollen producing floral parts. See pistillate.

Staminodes: Sterile stamens. See Parnassia parviflora.

Stellate: Star-like, as in hairs that have multiple branches and appear like a star-burst. Draba spp.

Stigma: The top of the pistil to which pollen can adhere.

Stipule: An often papery appendage, often leaf-like, usually occurring in pairs at the base of the petiole of a leaf. See Spergularia rubra.

Stolon: A slender modified stem running along the ground, rooting at the tip, and sprouting new plants. Strawberries have stolons. See Fragaria spp and  Erigeron flagellaris.

Streamsides: Moist areas along streams.

Strigose: Short, sharply pointed, stiff, appressed hairs. Erigeron argentatus.

Sub: Almost, as in subequal, subalpine, subentire, subcylindric, subcapitate.

Subalpine: From 10,000 to 11,500 feet.  Characterized by thick Spruce/Fir forests; Aspens grow at lower elevations in this zone.  Annually about 25-40 inches of moisture, most from snow (about 250-350 inches).  Lush wildflower growth mid-June through August.

Subsp:   Abbreviation for subspecies.  Also "ssp".

Subspecies: A taxonomic category below species, i.e., a division of species into two or more units each of which is clearly part of the same species but distinct enough in some characteristics to be differentiated from each other.  These small but obvious differences are often the result of geographic separateness whereas varieties of a species or subspecies usually exist in the same geographic area.  Abbreviated subsp. or ssp.

Subtend: Below and close to as in, "bracts subtend the inflorescence".

Sulcate: Grooved.

Superior: Attached above. Commonly used to describe the position of a flower's ovary in relation to the point of attachment of the petals and sepals. Hypogynous. Contrast with inferior. Arnica mollis.

Sympatric: Occupying the same geographic region.

Synonym: A botanical synonym is a species name that at one time was thought to be correct but was later found to be incorrect and was replaced by a new name.

For a number of reasons (see Plant Names), a species might acquire several scientific names. Unfortunately, there is no organization that determines which name is presently acceptable and which names are synonyms, incorrect, and not to be used. Each botanist makes this determination based on the authorities and research they accept. Botanists believe that agreement on one name will be reached over time. Unfortunately, until that agreement is reached, several names can be in use for the same plant.

On this web site I use plant names listed in the Taxonomic Data Center of BONAP by national plant authority John Kartesz.  BONAP names are in bold. Synonyms are not bold.

Click "Plant Names" for more information about how plants are named, how plants acquire a number of names, more details about synonyms, the complexity of naming plants, etc.

Taxa: Plural of "taxon", a biologic entity, such as, a genus, species, subspecies, or variety.

Taxonomy: The ordering of plants and animals according to established criteria.

Tepals:  The name given to the petal-like structures of a flower when these are not clearly differentiated into sepals and petals. See Opuntia and Eriogonum hookeri.

Terete: Round in cross section, cylindrical.

Ternate: Grouped into threes, as in a leaf divided into three leaflets. Lomatium triternatum.

Throat: A tubular corolla's slightly or significantly bulged or widened section that is found between the evenly elongated tube and the limb (the expanded, often lobed, tip of the corolla). See Penstemon comarrhenus. Not all tubular corollas have a widened throat; the tube can be evenly elongated to the limb. Not all floras use this term.

Thyrse: A compact panicle.

Tomentose: Densely clothed with matted, woolly hairs. See the very similar terms, lanate and villous.

Trichome: A general term for plant hair.

Trophophore: The sterile, leaf-like portion of Botrychium.

Tube: The evenly elongated lower section of a flower that has united petals. The tube sometimes expands into a throat which is topped by the limb (the expanded, often lobed, tip of the corolla). See Ipomopsis ramosa for a tube and limb.

Tubercle: An expanded structure common on some Cacti.  See Escobaria vivipara for close-up photographs of tubercles.

Tundra: Land above tree line characterized by a short growing season, intense sun and wind, thin soils, very high snow fall and high rain fall, and low growing sedges, grasses, dwarf shrubs, and herbs.

Turbinate: Top-shaped, inversely conical. Eriogonum cernuum.

Turions: Minute. rosebud-like shoots on the roots or at the base of the stems of some aquatic or semi-aquatic plants, such as, Epilobiums.

Type or type specimen: The first plant of its kind collected for science, submitted for classification purposes, and stored in an herbarium.  There are various types: The "holotype" is the one specimen that the first description and name are based on.  An "isotype" is a specimen collected at the same time as the holotype by the same person.  A "lectotype" is a specimen later designated as the type specimen when no holotype was originally designated. See "Type Locality" immediately below.

Type locality: Refers to the location where the type specimen was collected.  See "Type or Type Specimen" immediately above.

Umbel: A type of inflorescence in which each pedicel/peduncle, i.e., each flower or flower cluster stalk, grows upward and outward from one point in the same manner the spokes of an umbrella spread upward and outward from the umbrella main stem. The resultant flower cluster has a rounded top versus corymbs which have a flattened top. See Apiaceae (formerly the Umbelliferae Family) for examples. Cow Parsnip and Loveroot.

Compound umbels start with the pedicels originating from the same point and then branching again before a flower grows at the tip of each branching.

Corymb inflorescences are very similar to umbels but their pedicels do not originate from the same point on the main stem.

Unisexual: A flower with either stamens or pistils, but not both. Imperfect.

Var:  Variety.

Variety:  A taxonomic subunit of a species or subspecies.  Varieties of the same species or subspecies are distinct from each other because of some small variation in form. Some botanists believe that only one term, "subspecies" or "variety" should be used. It is also common to find one botanist calling the plant a subspecies while another calls it a variety. 

Vegetation Zone: As used in this web site, "vegetation zone" refers to those altitudes in which a plant best survives.

Ventral: The top side, as in the upper surface of a leaf. Adaxial. See dorsal.

Verticil: A whorl of parts about a central axis. See Marrubium vulgare.

Villous: Clothed with long, soft, unmatted hairs. See the very similar terms, lanate and tomentose.

Viscid: Sticky.

Vivaparous: Bearing live off-springs, i.e., in plants, reproducing not from flowers but from bulblets that grow on the parent plant. Lithophragma glabrum  Bistorta vivipara.

Vulgaris: Common.

Wetlands: Wet meadows, fens, seeps, etc.

Whorled: See leaf position.

Woodlands: Forested areas.

Woody: A plant whose stems become increasingly large and stiff with added years of growth.  The woody accumulation provides strength, protection for vital plant parts, and increased leaf production.  The latter ability allows for increased oxygen production and thus our existence.  Knock on wood!  See Herb.

Zygomorphic: Asymmetric. An irregular flower, one that is bilaterally symmetrical. Such a flower can only be divided in one way to produce mirror images. Penstemon spp. Contrast to actinomorphic (regular).

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