Stephanomeria exigua subsp. exigua

Illustrated
Synonyms: Stephanomeria pentachaeta D. C. Eaton Stephanomeria exigua var. pentachaeta (D. C. Eaton) H. M. Hall Stephanomeria schottii
Treatment appears in FNA Volume 19. Treatment on page 354. Mentioned on page 353, 355.

Heads in paniculiform arrays. Peduncles 10–40 mm, glabrous or sparsely glandular. Calyculi of appressed bractlets. Involucres glabrous or sparsely glandular. Florets 5–8. Cypselae 2.6–3.2 mm; pappi of 5–13 white to light tan bristles (widened bases persistent, bases connate in groups of 2–4, if bristles 5, breaking off completely, bristles plumose on distal 50%). 2n = 16.


Phenology: Flowering May–Jul.
Habitat: Sandy soils, deserts, sagebrush, creosote bush, pinyon-juniper woodlands, Joshua Tree communities
Elevation: 100–2000 m

Distribution

V19-556-distribution-map.gif

Ariz., Calif., Colo., Idaho, Nev., N.Mex., Oreg., Tex., Utah, Wash., Mexico (Baja California)

Discussion

Subspecies exigua is morphologically variable. Plants with pappi of 5 bristles (often called Stephanomeria pentachaeta) are found throughout its distribution; they are fully interfertile with plants having more bristles. Stephanomeria schottii A. Gray from southern Yuma County, Arizona, described as having a pappus of 4–6 bristles, “sparsely short-plumose toward the summit,” appears to be a synonym of subsp. exigua.

Selected References

None.

Lower Taxa

None.

"fine" is not a number.

rounded;acute +
scarious +
ovate +  and lanceolate +
paniculiform +
indeterminate +  and determinate +
L. D. Gottlieb +
Nuttall +
runcinate +, linear +  and oblanceolate +
3 cm30 mm <br />0.03 m <br /> (10 cm100 mm <br />0.1 m <br />) +
decurrent +
compound +  and simple +
runcinate;linear;oblong oblanceolate or spatulate +
tuberculate +, rugose +, muricate +  and smooth +
reflexed +  and appressed +
pubescent +  and glabrous +
filiform +
white +  and light tan +
zygomorphic +, actinomorphic +  and (3-)5-merous +
white +, lavender +  and pink +
light tan +  and dark-brown +
5-angled +  and columnar +
Ariz. +, Calif. +, Colo. +, Idaho +, Nev. +, N.Mex. +, Oreg. +, Tex. +, Utah +, Wash. +  and Mexico (Baja California) +
100–2000 m +
smooth +  and tuberculate +
winged +  and beaked +
dispersed +
Sandy soils, deserts, sagebrush, creosote bush, pinyon-juniper woodlands, Joshua Tree communities +
clustered +  and or +
indeterminate +
each +  and sessile +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
glandular +  and glabrous +
less cylindric;turbinate +
0.5 cm5 mm <br />0.005 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
cauline +  and basal +
2-carpellate +
white +  and tan +
persistent +
connate +  and distinct +
glandular +  and glabrous +
1 cm10 mm <br />0.01 m <br /> (4 cm40 mm <br />0.04 m <br />) +
Flowering May–Jul. +
connate +  and distinct +
5 +  and 12 +
subequal +  and unequal +
Trans. Amer. Philos. Soc., n. s. +
flat;convex +
slender +  and stout +
exalbuminous +
Illustrated +
branched +  and simple +
1 (?) +  and 8 (?) +
hairy +  and glabrous +
appendaged +  and truncate +
papillate +
Stephanomeria pentachaeta +, Stephanomeria exigua var. pentachaeta +  and Stephanomeria schottii +
Stephanomeria exigua subsp. exigua +
Stephanomeria exigua +
subspecies +
10 cm100 mm <br />0.1 m <br /> (200 cm2,000 mm <br />2 m <br />) +
shrub +  and subshrub +