Chamaechaenactis scaposa

(Eastwood) Rydberg

Bull. Torrey Bot. Club 33: 156. 1906.

Common names: Fullstem
IllustratedEndemic
Basionym: Chaenactis scaposa Eastwood Zoë 2: 231. 1891
Synonyms: Actinella carnosa A. Nelson Chamaechaenactis scaposa var. parva Preece & B. L. Turner
Treatment appears in FNA Volume 21. Treatment on page 395.

Plants densely cespitose, ± pulvinate; taproots deep; caudices thickly branched. Leaves strictly basal (old bases marcescent); longest petioles 3–40 mm, lengths mostly 1–2 times blades, proximally dilated and ± chartaceous; blades: largest 4–15 (–18) × 3–13 (–15) mm, coriaceous. Peduncles (1–) 5–30+, ascending to erect, (0–) 1–5 (–7) cm, ± strigose, usually villous (at least distally). Phyllaries: longest 9–17 mm; outer shorter than inner. Corollas 5–9 mm. Cypselae 5–8 mm; pappi: longest scales 4–7 mm. 2n = 32.


Phenology: Flowering late Apr–early Jul.
Habitat: Dry, open, relatively barren silty to clay soils from shale (sometimes petroleum-bearing), sandstone, marl, or limestone, often armored by rocky, sandy, or gravelly overburden, usually in pinyon-juniper woodlands
Elevation: 1400–2600 m

Distribution

V21-994-distribution-map.gif

Ariz., Colo., N.Mex., Utah, Wyo.

Discussion

Chamaechaenactis scaposa is grown and sold for use in rock gardens; it is considered a difficult horticultural subject. It is native to the Green, San Juan, and upper Colorado river basins in eastern Utah and western Colorado, extending to northeastern Arizona, northwestern New Mexico, and southwestern Wyoming. A previous report of C. scaposa from Idaho was in error.

Plants of Chamaechaenactis scaposa to the east and south tend to have heads and flowers larger, and leaves larger, more frequently ovate-cordate and distally crenate (var. scaposa), than plants to the west and north (var. parva), which also tend to have narrower and uniformly entire leaves (S. J. Preece and B. L. Turner 1953). Some recent collections from higher-elevation limestone sites at the western edge of the range of the species are reduced to a degree not originally included in var. parva, with heads ± sessile, embedded among dense leaves with blades scarcely reaching 5 mm. The two varieties appear to represent points within a broad, intermingled, clinal pattern of variation; they do not merit formal taxonomic recognition.

Selected References

None.

Lower Taxa

None.

"longest" is not a number.

... more about "Chamaechaenactis scaposa"
not tailed +, rounded +  and obtuse +
connate +  and distinct +
subequal +
scarious +
usually ovate +  and lanceolate +
usually deltate +  and lanceolate +
paniculiform +, cymiform +  and corymbiform +
indeterminate +  and determinate +
James D. Morefield +
(Eastwood) Rydberg +
decurrent +
Chaenactis scaposa +
compound +  and simple +
1.5 cm15 mm <br />0.015 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
1.3 cm13 mm <br />0.013 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
rounded;ovate;rounded;ovate;elliptic;cordate +
largest +
3mm;13mm +
winged;ribbed;winged;ribbed +
tuberculate +  and rugose +
barbellulate +  and barbellate +
connate +  and distinct +
Fullstem +
white +  and pinkish +
stipitate-glandular +  and hairy +
0.5 cm5 mm <br />0.005 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
piloso-strigose +
quadrangular +  and clavate +
fertile +  and bisexual +
fertile +  and bisexual +
Ariz. +, Colo. +, N.Mex. +, Utah +  and Wyo. +
1400–2600 m +
scabrellous +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
campanulate +  and cylindric +
Dry, open, relatively barren silty to clay soils from shale (sometimes petroleum-bearing), sandstone, marl, or limestone, often armored by rocky, sandy, or gravelly overburden, usually in pinyon-juniper woodlands +
indeterminate +
homogamous +  and heterogamous +
each +  and sessile +
0.6 cm6 mm <br />0.006 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
deltate +
1-2 times blades +
0.3 cm3 mm <br />0.003 m <br /> (4 cm40 mm <br />0.04 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
dentate to pinnatifid or palmatifid +  and entire +
distally more or less crenate revolute +  and more or less plane +
2-carpellate +
persistent +
oblanceolate +  and narrowly spatulate +
5 cm50 mm <br />0.05 m <br /> (7 cm70 mm <br />0.07 m <br />) +
villous +  and strigose +
1 cm10 mm <br />0.01 m <br /> (5 cm50 mm <br />0.05 m <br />) +
Flowering late Apr–early Jul. +
11 +  and 15 +
0.9 cm9 mm <br />0.009 m <br /> (1.7 cm17 mm <br />0.017 m <br />) +
Bull. Torrey Bot. Club +
bearing subulate enations +, hairy +  and bristly +
knobby;convex +
distinct +
4 +  and 20 +
exalbuminous +
Illustrated +  and Endemic +
subterranean +
prostrate +  and ascending +
appendaged +  and truncate +
hirsutulous +  and glabrous +
papillate +
Actinella carnosa +  and Chamaechaenactis scaposa var. parva +
Chamaechaenactis scaposa +
Chamaechaenactis +
species +
cylindric +
80 cm800 mm <br />0.8 m <br /> (300 cm3,000 mm <br />3 m <br />) +
1 cm10 mm <br />0.01 m <br /> (80 cm800 mm <br />0.8 m <br />) +
toothed +  and entire +
7 cm70 mm <br />0.07 m <br /> (9 cm90 mm <br />0.09 m <br />) +
2 cm20 mm <br />0.02 m <br /> (7 cm70 mm <br />0.07 m <br />) +
plant +  and cespitose +