Hymenoxys linearifolia Hooker, Icon. Pl. 2: plate 146. 1837

Annuals, 16–50+ cm. Caudices none. Stems 1–10, erect or ± decumbent, leafy, unbranched or branched distally. Leaves basal and cauline, ± hairy, ± gland-dotted; basal blades spatulate to oblanceolate, entire or with 2–6 teeth or lobes; proximal cauline blades narrowly spatulate or oblanceolate to linear-oblanceolate, entire or with 2–6 teeth or lobes; mid blades oblanceolate to linear-oblanceolate to linear, 0.9–9.5(–16) mm wide, entire or with 1–2 teeth or lobes; distal blades narrowly oblanceolate to linear-oblanceolate to linear, entire or with 1–2 teeth or lobes. Heads 8–50(–80) per plant, borne singly or in corymbiform arrays. Peduncles 8–29 cm, ± hairy. Involucres 5–10 × 7–15 mm. Outer phyllaries 8–21, 2.4–5.5 mm, margins 0–0.2 mm wide, not scarious or scarious, abaxial faces ± hairy. Ray florets 9–25; corollas 8.2–16.8 mm. Disc florets 50–200+; corollas yellow, 1.6–3 mm. Cypselae 1.5–2.6 mm; pappi of 4–8 obovate, often aristate scales 1–2.5 mm.

Varieties 2 (2 in the flora): sw United States, n Mexico.

Plants of Tetraneuris linearifolia morphologically intermediate between the two varieties are found in Bee, Duval, Live Oak, and McMullen counties, Texas.