Isocoma acradenia
Erythea 2: 111. 1894.
Herbage usually glabrous, sometimes minutely hispidulous, often stipitate-glandular, often resinous. Leaf blades oblanceolate to narrowly obovate, 20–150 mm, margins entire or toothed or lobed (teeth or lobes apically rounded-obtuse). Involucres 5–8 × 5–7 mm. Phyllary apices yellowish to greenish yellow, sometimes spinulose-aristate, usually not gland-dotted, usually with single, strongly developed, subepidermal resin pocket nearly as wide as bracts, sometimes a central pocket and 2+ smaller, lateral ones (resin pockets sometimes formed from numerous, coalesced, sessile glands). Florets 12–27; corollas 5–7(–8) mm. Cypsela ribs not forming apical horns.
Distribution
sw United States, nw Mexico.
Discussion
isocoma acradenia is distinctive in its whitish stems and narrow, whitish-indurate phyllaries with an apical resin pocket (or pockets). the leaves often occur in axillary fascicles
Varieties 3 (3 in the flora).
Selected References
None.
Lower Taxa
Key
| 1 | Leaves 50–150 mm; florets 20–27; phyllaryapices spinulose-aristate | Isocoma acradenia var. bracteosa |
| 1 | Leaves 20–50 mm; florets 12–24; phyllary apices usually rounded, not spinulose, sometimes with weakly developed aristae | > 2 |
| 2 | Leaves usually entire, proximal rarely toothed or lobed | Isocoma acradenia var. acradenia |
| 2 | Leaves all toothed to pinnatifid | Isocoma acradenia var. eremophila |