Shrubs, (100–)200–300 cm (sometimes subscandent, climbing and sprawling over other plants). Stems erect or clambering, intricately branched (often brittle, glabrous or nearly so, not viscid). Leaves cauline; opposite; petiolate; blades usually 3-nerved from bases, deltate, margins toothed, faces puberulent to velutinous (not gland-dotted). Heads discoid, in corymbiform arrays. Involucres obconic to hemispheric, 5–7 mm diam. Phyllaries persistent, 30–35 in 2–3+ series, obscurely nerved, lanceolate to subulate, unequal (herbaceous to chartaceous or membranous). Receptacles convex to conic, epaleate. Florets 30–50+; corollas usually blue to lavender, sometimes white, throats narrowly funnelform (lengths 1.5–2 times diams.); styles: bases not enlarged, glabrous, branches linear-filiform. Cypselae prismatic, 5–6-ribbed, sparsely scabrellous; pappi persistent, of ca. 35 barbellate bristles in 1 series. x = 10.

Distribution

Tex., ne Mexico.

Discussion

Species 1.

Selected References

None.

Lower Taxa

Tamaulipa azurea