Isocoma humilis

G. L. Nesom

Phytologia 70: 92. 1991.

Common names: Zion jimmyweed
EndemicConservation concern
Synonyms: Haplopappus leverichii Cronquist
Treatment appears in FNA Volume 20. Treatment on page 444. Mentioned on page 440.

Herbage villosulous or tomentose to sparsely hispidulous (hairs short, crisped, white), not resinous. Leaf-blades narrowly oblanceolate, 5–10 (–18) mm, margins usually toothed or lobed (teeth or shallow lobes in 1–2 (–3), pinnately arranged pairs), sometimes entire. Involucres 5–6 × 6–7 mm. Phyllary apices greenish, not aristate, gland-dotted, without resin pockets. Florets 19–28; corollas 4–5 mm. Cypsela ribs not forming apical horns.


Phenology: Flowering Sep–Oct.
Habitat: Sandy soils from red sandstone, pinyon-juniper-shrub
Elevation: 1000–1200 m

Discussion

Of conservation concern.

Isocoma humilis is known only from Washington County. It is recognized by its low stature (mostly 4–8 cm) and rounded habit, villosulous vestiture, small, toothed leaves, relatively large, many-flowered heads borne singly or in pairs, and small corollas and cypselae.

Selected References

None.

Lower Taxa

None.

"thick" is not a number.

... more about "Isocoma humilis"
not tailed +, rounded +  and obtuse +
distinct +
subequal +
scarious +
usually triangular +  and linear +
usually deltate +  and lanceolate +
spiciform +, racemiform +, paniculiform +  and corymbiform +
indeterminate +  and determinate +
Guy L. Nesom +
G. L. Nesom +
decurrent +
1 cm10 mm <br />0.01 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
oblanceolate +
linear;oblanceolate or obovate +
rugulose +  and muricate +
Zion jimmyweed +
not 2-lipped +  and actinomorphic +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
subterete +, terete +  and obpyramidal +
fertile +  and bisexual +
fertile +  and bisexual +
1000–1200 m +
gland-dotted;gland-dotted +
sericeous +, tomentose +, glabrous +, villous +  and hispidulous +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Sandy soils from red sandstone, pinyon-juniper-shrub +
indeterminate +
heterogamous +  and homogamous +
not resinous +
tomentose +  and sparsely hispidulous +
each +  and sessile +
0.5 cm5 mm <br />0.005 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
obconic;turbinate or campanulate +
0.6 cm6 mm <br />0.006 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
shallow +
deltate +
dentate to pinnatifid +  and entire +
lobed +  and toothed +
2-carpellate +
persistent +
Flowering Sep–Oct. +
oblong +  and elliptic-lanceolate +
styliferous +, neuter +  and pistillate +
bearing subulate enations +, hairy +  and bristly +
concave;usually flat;conic +
exalbuminous +
Endemic +  and Conservation concern +
eglandular +  and few-branched +
resinous +
gland-dotted +
stipitate-glandular +, tomentose +, villous +, hispidulous +  and glabrous +
appendaged +  and truncate +
papillate +  and smooth +
Haplopappus leverichii +
Isocoma humilis +
species +
goblet--shaped +
ampliate +
dark orange-resinous +
120 cm1,200 mm <br />1.2 m <br /> (150 cm1,500 mm <br />1.5 m <br />) +
20 cm200 mm <br />0.2 m <br /> (120 cm1,200 mm <br />1.2 m <br />) +
120 cm1,200 mm <br />1.2 m <br /> (150 cm1,500 mm <br />1.5 m <br />) +