Isocoma coronopifolia

Herbage usually glabrous, leaves never stipitate-glandular, almost always resinous. Leaf-blades oblanceolate, 15–30 (–50) mm, margins usually pinnatifid (lobes in 1–3 pairs, spreading, linear, apically spinescent), sometimes entire or only proximal leaves pinnatifid. Involucres 5–6 (–7) × 2.5–4 mm. Phyllary apices green to greenish yellow or yellowish (markedly thickened), not aristate, slightly or not gland-dotted, without resin pockets. Florets 12–15; corollas 4.5–6 mm. Cypsela ribs not forming hornlike extensions. 2n = 12.

Phenology: Flowering (May–)Jun–Oct.
Habitat: Alkaline sandy flats, matorral, shrublands
Elevation: 200–500 m

Tex., Mexico (Coahuila), Mexico (Nuevo León), Mexico (Tamaulipas)

Discussion

Populations with at least the distal leaves entire have been called Isocoma pedicellata, and these apparently segregate geographically, at least to some extent (G. L. Nesom 1991c). Some plants have both entire and pinnatifid leaves; the distinction does not appear to warrant formal recognition.

Selected References

None.

Lower Taxa