Workshop 1 names

Leaves

Please Note: All photographs are copyright by the photographers and none can be reproduced in any form without the expressed consent of the photographers. For permission to use photographs, email Al.

Leaf margins

Lobes and sinuses

Sidalcea neomexicana

Serrations and teeth

Betula-fontinalis

Leaf surfaces

Glabrous

Goodyera oblongifolia

Pubescent

Senecio atratus

Leaf modifications

Scales

Sabina osteosperma

Needles

Picea pungens

Spines

Opuntia polyacantha

Bracts

Castilleja chromosa

Phyllaries

Erigeron compositus

Stem and leaf growth patterns

Appressed: close to or flat against
Ascending: growing upward in a curved fashion
Caespitose: growing in a dense tuft
Declining: curved downward
Decumbent: growing along the ground with an ascending tip
Divergent: spreading
Erect: vertical, not declining or spreading
Ramose: many branched
Recumbent: growing along the ground
Reflexed: sharply declining

Other Stem, Leaf, and Plant Terms

Acaulescent: without a stem, all leaves basal
Adnate: fusion of unlike structures
Cauline: on the stem, as in "cauline leaves"
Caudex: woody base of herbaceous plant
Connate: fusion of like structures
Depauperate: diminutive
Distal: opposite the point of attachment
Herbaceous: fleshy (versus woody)
Internode: distance between point of attachment of leaves on a stem
Involute: rolled inward (as in leaves)
Node: point of attachment of leaves on a stem
Petiole: the leaf stalk
Proximal: at or near the point of attachment
Stipule: tiny leaf-like structures at the base of the petiole
Sub: almost
Revolute: rolled outward (as in leaves)
Rhizomes, rhizomatic, rhizomatous: underground roots which sometimes give rise to new plants
Stolon: a modified horizontal stem that emanates from the base of a plant and roots at its nodes

Hairs (pubescence)
Hairs are generally called "trichomes" and
hairiness is generally referred to as "pubescence".
**Plants of the same species will not always have the same level of pubescence.

Canescent (white/gray cast from short hairs)

Tetradymia canescens

Strigose (appressed, pointed, short)

Ximenesia encelioides

Glandular (sticky, round at tip, often with a noticeable smell)

Geum macrophyllum

Ribes montigenum

Tomentose, villous (dense, woolly, matted or loose)

Machaeranthera pinnatifida

Pilose (long, soft)

Pulsatilla ludoviciana

Stellate (elevated from surface, as shown below,
or flattened on surface)

Draba cuneifolia

Hirsute (course, curved)

Coriflora hirsutissima

Ciliate (Click to see "Bracts" above)

A few terms for hairs:

Canescent: gray/white appearing because of fine hairs
Ciliate: with marginal hairs
Glandular: with glands, sticky
Hirsute: hairy with course, stiff hairs
Pilose: long, soft, straight hairs
Puberulent: minutely pubescent
Pubescent: hairy
Pustulose: swellings at the base of hairs
Sericeous: silky
Stellate: forked, star-burst-like
Strigose: pointed, straight, appressed hairs
Tomentose: densely clothed with woolly hairs
Trichome: a general term for plant hair
Villous: clothed with long, soft hairs

Important reminder

Just because a plant has one or more of the above words in its name, it does not follow that the plant possess those characteristics. The person who named the plant may have incorrectly named it, may have had specimens that were not typical, or may have named it relative to other plants, e.g., not all plants named "grandiflora" have large flowers; the flowers may be "grand" relative to flowers of other members of that genus.

Questions about evolution

Why do plants have hairs?

Why do some plants have hairs and others do not?

Why do some plants have straight hairs and other plants have curved hairs?

Why do some plants in a species have hairs and others of the same species do not have hairs?