2.
Psilostrophe sparsiflora
(A. Gray) A. Nelson, Proc. Biol. Soc. Wash. 16: 23. 1903.
Riddellia tagetina
Nuttall var.
sparsiflora
A. Gray in A. Gray et al., Syn. Fl. N. Amer. 1(2): 318. 1884
Biennials or perennials
(rarely flowering first year), 10—40+ cm.
Stems
± strigillose (greenish, sometimes ± villous in proximal axils).
Heads
in ± corymbiform arrays.
Peduncles
8—12(—25+) mm.
Involucres
4—6 mm.
Ray florets
(1—)2—3(—4); corolla laminae (6—)8—10+ mm, reflexed in fruit.
Disc florets
7—9.
Cypselae
usually glabrous, sometimes gland-dotted;
pap-pi
of 4—5 lanceolate to lance-subulate scales 2—3 mm.
2
n
= 32.
Flowering May—Sep. Grasslands, pinyon-juniper scrub, sagebrush scrub, yellow pine forests; 900—2200 m; Ariz., N.Mex., Utah.
