Tetraneuris linearifolia (Hook.) Greene

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

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.

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

Tetraneuris oblongifolia Greene, Pittonia 3: 269. 1898
Telraneuris Unearifolia oblongifolia Cockerell, Proc. Biol. Soc. Wash. 17: 112. 1904.
A biennial or perhaps even a perennial, with a tap-root; stem 3 dm. high, simple at the base, often branched above; basal leaves clustered, oblanceolate, 3-6 cm. long, 4-6 mm. wide, copiously covered by long brownish hairs; stem-leaves linear, 1-2 mm. wide; peduncles 5-12 cm. long; involucre 4-5 mm. high, 6-10 mm. broad; ligules 8-9 mm. long, about 4 mm. wide; disk-corollas 2.5 mm. long, glandular-puberulent ; achenes 2 mm. long, densely silky; squamellae 1.5 mm. long, ovate, acuminate into a short awn-point.
Type locality: Guajuco, Nuevo Leon. Distribution: Texas and New Mexico to Nuevo Leon.

Tetraneuris linearifolia (Hook.) Greene, Pittonia 3: 269
1898.
Hymenoxys linearifolia Hook. Ic. pi. 146. 1837. Actinella linearifolia T. & G. Fl. N. Am. 2: 383. 1842. Ptilepida linearifolia Britton, Mem. Torrey Club 5: 340. 1894. Picradenia linearifolia Britton; Britt. & Brown, 111. Fl. 3: 448. 1898.
A slender and branched annual, with a tap-root, in Mexico perhaps becoming perennial; stem sparingly long-hairy, 2-3 dm. high; lower leaves linear-oblanceolate, short-petioled, 2-4 cm. long, sparingly long-hairy; upper leaves narrowly linear; peduncles 3-10 cm. long; involucre 5 mm. high, 5-7 mm. broad, silkyvillous; bracts oblong; ligules 5-6 mm. long, 3 mm. wide; disk-corollas 2 mm. long; achenes 2 mm. long, densely hairy; squamellae lanceolate or ovate, 1 mm. long, excluding the awn produced by the excurrent midrib.
Type locality: San Felipe, Texas.
Distribution: Oklahoma, Texas. Coahuila, and Nuevo Leon.

Tetraneuris latior (Cockerell) Rydberg, sp. nov
Telraneuris Unearifolia latior Cockerell, Proc. Biol. Soc. Wash. 17: 111. 1904.
A branched annual, with a tap-root; stem 2-3 dm. high, leafy, sparingly long-hairy or glabrate; leaves, all except the uppermost, linear-oblanceolate or oblanceolate, 3-6 cm. long, 2-6 mm. wide; peduncles 5-15 cm. long; involucre 6 mm. high, 10 mm. broad, silkyvillous; ligules 8-10 mm. long, about 4 mm. wide; disk-corollas 3 mm. long; achenes 3 mm. long, densely hirsute; squamellae ovate; midvein excurrent into a short awn.
Type locality: Kerrville, Texas. Distribution: Texas to Nuevo Leon.

Tetraneuris dodgei (Cockerell) Rydberg, sp. nov
Tetraneuris Unearifolia Dodgei Cockerell, Proc. Biol. Soc. Wash. 17: 112. 1904.
A caulescent biennial, with a tap-root; stem 2-3 dm. high, sparingly long-villous, simple below, branched above; basal leaves clustered, narrowly oblanceolate, some of them usually lobed, 3-5 cm. long, 2-4 mm. wide, conspicuously long-hairy; stem-leaves narrowly linear, 1-2 mm. wide; peduncles 5-10 cm. long; involucre about 5 mm. high and 10 mm. broad, villous; bracts oblong, obtuse; ligules about 8 mm. long and 4 mm. wide; disk-corollas 3 mm. long; achenes 2 mm. long, densely hirsute; squamellae obovate, the body 1 mm. long, the midrib excurrent into an awn fully as long.
Type locality: Monterey, Nuevo Leon. Distribution: Texas to Nuevo Leon.

Tetraneuris linearifolia is a North American species of plants in the sunflower family, known by the common name fineleaf fournerved daisy. It grows in the south-central United States (Kansas, Oklahoma, Texas, New Mexico) and northern Mexico (Coahuila, Nuevo León, Tamaulipas).

Tetraneuris linearifolia is an annual herb up to 50 cm (20 in) tall. It forms a branching underground caudex sometimes producing as many as 10 above-ground stems. One plant can produce as many as 80 flower heads. Each head has 9–25 yellow ray flowers surrounding 50-200 yellow disc flowers.

Tetraneuris linearifolia là một loài thực vật có hoa trong họ Cúc. Loài này được (Hook.) Greene miêu tả khoa học đầu tiên năm 1898.