Calycoseris

A. Gray

Smithsonian Contr. Knowl. 5(6): 104, plate 14. 1853

Common names: Tack-stem
Etymology: Greek kalyx, cup, and seris, chicory, alluding to shallow cups on apices of cypselae
Treatment appears in FNA Volume 19. Treatment on page 307. Mentioned on page 216, 310, 360.
Annuals, 5–30 cm; taprooted. Stems 1–3, erect or ascending, branched from bases; distal stems, branches, and involucres conspicuously dotted with short, stipitate, flat-topped glands that resemble tacks. Leaves basal and cauline; alternate; sessile; basal blades pinnately lobed (lobes narrow, linear, often delicate, spreading, margins entire, smooth); distal reduced to linear, entire bracts. Heads borne singly or in open, cymiform arrays. Peduncles (1–3 cm) not inflated, not bracteate. Calyculi of 8–16, reflexed, unequal bractlets (lengths to 1/2 phyllaries). Involucres campanulate, 5–12+ mm diam. Phyllaries 12–20 in 1 series, linear-lanceolate, equal, margins scarious, apices acute. Receptacles flat, smooth, bristly, epaleate (each floret subtended by 1 fine, capillary bristle). Florets ca. 25; corollas white or yellow (showy). Cypselae tan to brown, fusiform, beaked, ribs 5, separated by longitudinal grooves, faces glabrous or scabridulous; pappi (borne on denticulate cups at beak tips) falling (together), of 50–60+, white, basally connate, smooth bristles 5–8(–9) mm in 1 series. x = 7.

Distribution

sw United States, nw Mexico.

Discussion

Species 2 (2 in the flora).

Selected References

None.

Key

1 Ligules yellow; tack-shaped glands red- or purple-tipped; cypselae deeply grooved between ribs, faces not rugulose Calycoseris parryi
1 Ligules white; tack-shaped glands straw-colored; cypselae shallowly grooved between ribs, faces weakly cross-rugulose Calycoseris wrightii