Roldana

Perennials or subshrubs [shrubs, or trees], [20–]60–100(–300)[–800] cm (caudices woody, fibrous-rooted, often woolly). Stems single or clustered, erect (glabrous or arachnose and glabrescent [tomentose to lanate]). Leaves mostly cauline (at flowering); alternate; petiolate; blades pinnati-palmately [pinnately or palmately] nerved, suborbiculate (proximal) to ovate or oblong (distal) [deltate, elliptic, lanceolate, orbiculate, or ovate], sinuately to angularly lobed (± polygonal) [palmately, pinnately, or not lobed], ultimate margins serrate to denticulate (lobes and denticles apiculate) or entire, abaxial faces glabrous or arachnose [tomentose to lanate] and glabrate, adaxial glabrous or glabrate [tomentose to lanate]. Heads radiate [disciform or discoid], in corymbiform or paniculiform arrays (peduncles usually arachnose). Calyculi 0 or of 1–3(–5)[–13+] (linear [filiform to foliaceous]) bractlets. Involucres campanulate [hemispheric to cylindric or funnelform], 3–5[–20+] mm diam. Phyllaries persistent, (5–)8–13+ in 2 series, erect, distinct, lanceolate or lance-linear to linear (± navicular), equal, margins ± scarious. Receptacles flat, alveolate (margins of sockets raggedly toothed), epaleate. Ray florets [0 or 3–]5–8, pistillate, fertile; corollas yellow or yellow-orange [whitish or ochroleucous] (laminae usually oblong to elliptic). Disc florets 6–30[–100+], bisexual, fertile; corollas yellow or yellow-orange [whitish or ochroleucous], tubes shorter to longer than funnelform to campanulate throats, lobes 5, recurved, deltate to lance-ovate; style branches: stigmatic areas continuous, apices rounded-truncate. Cypselae ± columnar, [5- or] 10-ribbed, puberulent (between ribs) [glabrous]; pappi persistent (fragile), of 40–80+, white, barbellulate bristles in 1 series. x = 30.

Distribution

sw United States, Mexico, Central America.

Discussion

Species ca. 50 (1 in the flora).

Selected References

None.

Lower Taxa

Roldana hartwegii