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Click to read about the various Rabbitbrush species in the Four Corners region and how the Chrysothamnus genus shown on this page differs from the Ericameria genus.

Chrysothamnus depressus

Chrysothamnus depressus

Chrysothamnus depressus

Chrysothamnus depressus

Chrysothamnus depressus (Low Rabbitbrush)
Asteraceae (Sunflower Family)

Foothills. Open woodlands, meadows. Summer, fall.
Lone Mesa State Park, August 1, 2009and
Carpenter Natural Area, Cortez, August 20, 2016.

This low shrub (hence "depressus", Latin for "flattened or pressed down"), can be uncommon to abundant.  Professional floras indicate that the plant is no more than 18 inches tall, but plants in the two photographs immediately above are 20 to 25 inches tall, and the plant is commonly 20 or more inches tall in the Carpenter Natural Area.

Although Chrysothamnus depressus flowers are small (about 9-15 mm in length), they are about twice as long as as those of C. greenei and C. viscidiflorus, two other Chrysothamnus in our area.

When C. depressus occurs in large numbers (as it commonly does) it is a conspicuous and attractive shrub -- even in its fall color of golden brown.

Chrysothamnus depressus was found for science in the 1830s by Thomas Nuttall and he named and described it in 1848.

Chrysothamnus depressus 

Chrysothamnus depressus 

Chrysothamnus depressus

Chrysothamnus depressus (Low Rabbitbrush)
Asteraceae (Sunflower Family)

Foothills. Open woodlands, meadows. Summer, fall.
Lone Mesa State Park, August 1, 2009,
Carpenter Natural Area, Cortez, August 20, 2016,
Can-Do Trail, McPhee Reservoir, September 17, 2010.

The phyllaries are sharply pointed and strongly ribbed ("keeled") giving the flower head a prickly and angular appearance. They are in 4–6 series, in 5 strong vertical ranks and have obvious mid-nerves.

                                               Chrysothamnus depressus

Once the bright yellow flowers open (second photograph at left), the angularity is added to by the sharply pointed lobes of the corolla. 

The third photograph at left shows the silky pappus hairs which are long (5.5 to 7.5 mm), numerous, and quite evident after the flowers have faded.

Leaves are commonly closely pressed against the stems and they are frequently similar to the phyllaries in their pointed (acute) tips. They have evident mid-nerves, are linear to oblanceolate or narrowly oblong, 7–30 × 1.5–7 mm, flat to keeled.

                                               Chrysothamnus depressus

 

Chrysothamnus greenei

Chrysothamnus greenei

Chrysothamnus greenei (Greene's Rabbitbrush)
Asteraceae (Sunflower Family)

Foothills. Shrublands, woodlands, meadows. Summer, fall.
Carpenter Natural Area, August 20, 2016 and November 5, 2019.

Chrysothamnus greenei 

Chrysothamnus greenei

Chrysothamnus greenei

Chrysothamnus greenei (Greene's Rabbitbrush)
Asteraceae (Sunflower Family)

Foothills. Shrublands, woodlands, meadows. Summer, fall.
Carpenter Natural Area, August 17, 2016 and November 5, 2019.

Chrysothamnus greenei

Chrysothamnus greenei

Chrysothamnus greenei

Chrysothamnus greenei (Greene's Rabbitbrush)
Asteraceae (Sunflower Family)

Foothills. Shrublands, woodlands, meadows. Summer, fall.
Carpenter Natural Area, August 17, 2016.

Although Chrysothamnus greenei is uncommon in the Four Corners area, when it is found it is often abundant and it gives a golden glow to the area from its numerous plants with innumerable flowers.

According to all floras I have examined, Chrysothamnus greenei grows to a maximum of 50 cm tall (that's 19.7 inches), but the plants shown on this page are 20 to 25 inches tall and many in the Carpenter Natural Area of Cortez exceed 50 cm.

Disk corollas are no more than 5.5 mm long. Flower clusters are numerous and crowded atop new twig growth that is light green and this tops the previous few years of twig growth that is white and peels off in small scales when you scratch the surface. Older twigs become gray and fibrous on the surface.

Leaves are quite narrow; as shown here they are just a millimeter wide but they may be up to 2 mm wide. They can be from 10 to 40 mm long (as shown here about 22 mm long) and sometimes the leaves have a twist to them. They are glabrous.

Much of the plant is covered with a resinous exudation that has a very pleasant smell.

Chrysothamnus greenei is very similar to Chrysothamnus viscidiflorus (shown below) and the two are difficult to tell apart unless one examines the flower heads with a magnifying glass, or if they are fully mature plants. Then C. viscidiflorus is easy to spot as it is twice as tall as C. greenei. See below for other differences in the two species.

Chrysothamnus greenei was at first named Bigelovia greenei by Asa Gray in 1876 from a collection made by Edward Greene in Colorado in 1872. Greene gave the plant its present name in 1895. Greene was a respected collector, botanical author, and preacher. (Click for more biographical information about Greene.)

Chrysothamnus greenei

Chrysothamnus greenei (Greene's Rabbitbrush)
Asteraceae (Sunflower Family)

Foothills. Shrublands, woodlands, meadows. Summer, fall.
Carpenter Natural Area, August 20, 2016.

Phyllaries are unequal in length, in 3–4 series, in vertical ranks, and they are tan to light green (especially toward the finely drawn out tip).

 

Chrysothamnus greenei

Chrysothamnus viscidiflorus

Chrysothamnus viscidiflorus variety viscidiflorus (Sticky Rabbitbrush)
Asteraceae (Sunflower Family)

Semi-desert, foothills, montane. Woodlands, meadows, disturbed areas. Late summer, fall.
Point Lookout Trail, Mesa Verde National Park, November 30, 2017 and
Canyons of the Ancients National Monument, August 21, 2005.

Chrysothamnus viscidiflorus

Chrysothamnus viscidiflorus variety viscidiflorus (Sticky Rabbitbrush)
Asteraceae (Sunflower Family)

Semi-desert, foothills, montane. Woodlands, meadows, disturbed areas. Late summer, fall.
Carpenter Natural Area, Cortez, August 20, 2016.

Chrysothamnus viscidiflorus

Chrysothamnus viscidiflorus

Chrysothamnus viscidiflorus variety viscidiflorus (Sticky Rabbitbrush)
Asteraceae (Sunflower Family)

Semi-desert, foothills, montane. Woodlands, meadows, disturbed areas. Late summer, fall.
Canyons of the Ancients National Monument, August 21, 2005 and Can-Do Trail, McPhee Reservoir, September 17, 2010.

Chrysothamnus viscidiflorus blooms in late summer-to-fall with an abundance of tiny flowers clustered into a golden-yellow glow.  The shrub is usually evenly rounded, it is typically several feet tall (but may be over three), the base of the flower cluster is commonly sticky (hence the Latin "viscidiflorus", meaning "sticky flower"), its leaves are commonly twisted into a gentle spiral, and the stems are smooth without a whitish, hairy coating. Ericameria nauseosus, a very common species with which C. viscidiflorus is commonly confused, has white-hairy stems and often grows five to six feet tall and round.

The lumpy projections beneath the golden-yellow flower heads are the phyllaries that cover the incipient flowers and then open and subtend the flowers. The shape, arrangement, and color of phyllaries varies from one member of the Sunflower Family to another and thus these characteristics help distinguish species.

The phyllaries of Chrysothamnus viscidiflorus are variable; they may be overlapping in a vertical line (as shown here) or they may spiral; there may be anywhere from 12 to 24 phyllaries; their shape varies significantly; they may be hairy or not; their tips may be pointed or rounded; etc.

The physical characteristics of C. viscidiflorus phyllaries are quite similar to those of C. greenei shown above and it is easy to confuse the two species -- especially when C. viscidiflorus is young. They differ as follows:

1) C. viscidiflorus commonly grows to a meter tall and even to 1 1/2 meters tall; C. greenei grows to a bit over half of a meter tall.

2) C. viscidiflorus leaves are linear to lanceolate, 10–75 long × 0.5–10 wide mm and they have a visible mid-vein and two or four side veins; C. greenei leaves are linear-filiform, 10–40 long × 0.5–2 wide and they have one faint mid-vein.

3) C. viscidiflorus phyllaries have acute to obtuse tips, mid-veins usually visible (at least distally); C. greenei phyllaries have acuminate tips, mid-veins rarely visible.

4) C. viscidiflorus flower heads are up to 7 cm wide; C. greenei flower heads are up to 4 cm wide.

Welsh notes in his A Utah Flora that C. viscidiflorus and C. greenei do hybridize, forming plants with intermediate characteristics.

The first specimens of C. viscidiflorus were collected by David Douglas along the Columbia River in 1826 and the plant was first named Crinitaria viscidiflora by William Hooker in 1834. In 1841 Thomas Nuttall gave the plant its present name. "Viscidiflorus" means "sticky flowered".

Chrysothamnus viscidiflorus

Chrysothamnus viscidiflorus variety viscidiflorus (Sticky Rabbitbrush)
Asteraceae (Sunflower Family)

Semi-desert, foothills, montane. Woodlands, meadows, disturbed areas. Late summer, fall.
Canyons of the Ancients National Monument, August 21, 2005.

Chrysothamnus viscidiflorus

Chrysothamnus viscidiflorus variety viscidiflorus (Sticky Rabbitbrush)
Asteraceae (Sunflower Family)

Semi-desert, foothills, montane. Woodlands, meadows, disturbed areas. Late summer, fall.
Can-Do Trail, McPhee Reservoir, September 17, 2010 and Canyons of the Ancients National Monument, August 12, 2013.

Leaves of this variety of C. viscidiflorus are commonly twisted and glabrous (or sometimes ciliate).

                                             Chrysothamnus viscidiflorus.

Range map © John Kartesz,
Floristic Synthesis of North America

State Color Key

Species present in state and native
Species present in state and exotic
Species not present in state

County Color Key

Species present and not rare
Species present and rare
Species extirpated (historic)
Species extinct
Species noxious
Species exotic and present
Native species, but adventive in state
Eradicated
Questionable presence

Range map for Chrysothamnus depressus

Chrysothamnus greenei

Range map for Chrysothamnus greenei

Range map for Chrysothamnus viscidiflorus