Difference between revisions of "Packera millelobata"

Revision as of 20:24, 16 December 2019

Perennials, 30–50+ cm; taprooted or ± rhizomatous (bases weakly creeping, horizontal to erect). Stems 1 or 2–5+, loosely clustered, glabrous or leaf axils sparsely tomentose. Basal leaves (and proximal cauline) petiolate; blades narrowly lanceolate (pinnatifid, lateral lobes 6+ pairs, their bases petioluliform, terminal lobes smaller than laterals), 60–100 × 10–20 mm, bases tapering, ultimate margins dentate. Cauline leaves gradually reduced (sessile). Heads 6–20+ in corymbiform arrays. Peduncles bracteate or ebracteate, glabrous. Calyculi inconspicuous. Phyllaries (13–)21, green (tips yellow), 4–6+ mm, glabrous. Ray florets (8–)13; corolla laminae 8–10+ mm. Disc florets 40–55+; corolla tubes 2–3 mm, limbs 2–3 mm. Cypselae 1–1.5 mm, hirtellous on ribs; pappi 3.5–4.5 mm.

Phenology: Flowering late Mar–early Jun.
Habitat: Streambeds, openings in wooded areas on limestone-derived soils or on igneous-derived soils that are damp during growing season
Elevation: 1400–2100 m

Tex., Mexico (Chihuahua, Coahuila).

Discussion

In the flora area, Packera millelobata occurs only in the trans-Pecos region of western Texas. It has been confused with P. tampicana. Their ranges overlap along the Rio Grande; P. millelobata has leaves with narrow terminal lobes; P. tampicana has terminal lobes as wide as the leaf blade. In addition, P. tampicana is annual with pronounced taproots; P. millelobata is perennial with taprooted caudices.

Selected References

None.

Lower Taxa