Linnaea 6: 511. 1831.

Etymology: Greek thele, nipple, and sperma, seed, alluding to papillate cypselae of original species
Treatment appears in FNA Volume 21. Treatment on page 199. Mentioned on page 184.

Annuals, perennials, or subshrubs, 10–70+ cm. Stems usually 1, erect, branched distally or ± throughout. Leaves mostly basal, basal and cauline, or mostly cauline; mostly opposite (distal rarely alternate); blades usually 1(–3)-pinnately lobed (ultimate lobes oblanceolate to filiform), faces usually glabrous, rarely hairy. Heads radiate or discoid, borne singly or in loose, corymbiform arrays. Calyculi of 3–8+ distinct, usually spreading or reflexed, usually linear to subulate, herbaceous bractlets. Involucres hemispheric to urceolate, 4–15+ mm diam. Phyllaries 5–8 in ± 2 series, persistent, connate 1/5–7/8+ their lengths, lance-ovate to ovate, ± equal, ± leathery to membranous, margins (of distinct apices) scarious. Receptacles flat to convex, paleate; paleae falling, (whitish with red-brown striae, each ± appressed to abaxial face of subtended cypsela), obovate to oblong, scarious. Ray florets 0 or ca. 8, neuter; corollas yellow or red-brown, or bicolored (yellow and red-brown). Disc florets 20–100+, bisexual, fertile; corollas yellow (with red-brown nerves) or red-brown, either with throats equal to or longer than 5, ± deltate, ± equal lobes, or with throats shorter than 5, ± lance-linear, ± unequal lobes (in either form, the abaxial sinus usually ± deeper than others). Cypselae (dark red-brown or stramineous) outer often arcuate, shorter, inner more columnar, usually some or all ± obcompressed (each usually shed together with its subtending palea), faces smooth or papillate to tuberculate or verrucate, margins sometimes ± winged; pappi 0, or persistent, of 2 retrorsely ciliate, subulate scales or awns. x = 12.


w North America, Mexico, South America.


Species 10+ (9 in the flora).


1 Throats of disc corollas equal to or longer than lobes; pappi usually 0, rarely of 2 awns 0.1–0.3(–0.5) mm > 2
1 Throats of disc corollas shorter than lobes; pappi usually of 2 awns or scales (0.5–)1–3 mm, rarely 0 > 4
2 Cauline leaves ± scattered over proximal 3/4+ of plant heights, internodes mostly 45–95 mm Thelesperma simplicifolium
2 Cauline leaves ± crowded over proximal 1/4–1/2 of plant heights, internodes mostly 5–25+ mm or 1–5(–35) mm > 3
3 Leaf lobes mostly linear to filiform, 5–25(–45+) × 0.5(–1) mm; cypselae 2–3 mm Thelesperma longipes
3 Leaf lobes mostly oblanceolate to linear, (5–)10–35(–45+) × (1–)2–3(–5) mm; cypselae 5–7 mm Thelesperma subnudum
4 Perennials (sometimes flowering first year); calyculi of 3–5+, ovate to oblong bractlets 1–3 mm; ray florets 0, or 8, laminae 4–8(–12+) mm; cypselae (4–)5–8 mm > 5
4 Annuals (sometimes persisting); calyculi of 5–9, linear to narrowly triangular bractlets (2–)4–8+ mm; ray florets 8, laminae 10–20+ mm; cypselae 3.5–5.5+ mm > 6
5 Plants 10–30(–50) cm; ray florets usually 8, rarely 0; disc corollas red-brown Thelesperma ambiguum
5 Plants (20–)30–80+ cm; ray florets 0; disc corollas yellow Thelesperma megapotamicum
6 Ray laminae proximally to wholly red-brown to purplish, or each with a proximal red-brown spot; disc corollas red-brown to purplish > 7
6 Ray laminae yellow to golden (rarely proximally suffused with red-brown); disc corollas yellow or red-brown > 8
7 Calyculi of 5–6(–9), linear to narrowly triangular bractlets (margins hispido-ciliate); cypselae 3.5–4 mm Thelesperma burridgeanum
7 Calyculi of 6–7+, narrowly triangular bractlets (margins not ciliate); cypselae 5–5.5+ mm Thelesperma nuecense
8 Plants 30–70(–120+) cm; cauline leaves ± scattered over proximal 9/10 of plant heights, internodes 35–100+ mm; disc corollas yellow, often with brown nerves Thelesperma flavodiscum
8 Plants 10–40(–70+) cm; cauline leaves crowded to ± scattered over proximal 1/2–3/4+ of plant heights, internodes mostly 10–35(–50+ mm); disc corollas red-brown or yellow with red-brown nerves Thelesperma filifolium
... more about "Thelesperma"
John L. Strother +
Lessing +
w North America +, Mexico +  and South America. +
Greek thele, nipple, and sperma, seed, alluding to papillate cypselae of original species +
greer1997a +  and hansen2002a +
Undefined (tribe Undefined) subtribe Coreopsideae +  and Undefined (tribe Undefined) subtribe Petrobiinae +
Thelesperma +
Asteraceae (tribe Heliantheae) subtribe Coreopsidinae +