Mem. Amer. Acad. Arts, n. s. 4: 106. 1849.
Subshrubs [shrubs], (10–)20–30+ cm (± succulent, sometimes rhizomatous). Stems erect. Leaves cauline; mostly alternate [opposite]; ± sessile; blades linear to filiform (± terete) [lance-linear], margins entire, faces glabrous (not gland-dotted). Heads discoid, borne singly [in corymbiform arrays]. Involucres obconic, [3–]5–8 mm diam. Phyllaries persistent, [30–]45–60 in [2–]4–5 series ± appressed, lance-linear to subulate, unequal, resinous-nerved. Receptacles conic, paleate; paleae falling, linear, scarious, flat or weakly conduplicate, resinous-veined. Ray florets 0. Disc florets 60–150+, bisexual, fertile; corollas greenish yellow, tubes shorter than or about equaling campanulate to cylindric throats, lobes 5, narrowly deltate. Cypselae columnar to clavate, ribs 8–15, faces glabrous; pappi 0 [bristles]. x = 18.
Species 2 (1 in the flora).