Rayjacksonia aurea (A. Gray) R. L. Hartman & M. A. Lane

Rayjacksonia aurea is now restricted to a few, small populations in the vicinity of Houston. It is in the Center for Plant Conservation’s National Collection of Endangered Plants.

Annuals, 20–100 cm, herbaceous. Leaf blades linear to linear-oblanceolate, mid-cauline 1–3(–4) mm wide. Heads on short, sometimes bracteate peduncles, not surpassed by distal leaves. Involucres 4–7 × 10–15 mm. Phyllaries in 4–5 series, tightly appressed, strongly unequal, apices erect to slightly spreading, ca. 1 mm wide, herbaceous. Ray florets 14–19; corollas 6.5–9.5 mm. Disc florets: corolla tubes ± equaling limbs. 2n = 12.

Haplopappus aureus A. Gray, Mem. Amer. Acad. Arts, n. s. 4: 76. 1849 (as Aplopappus); Machaeranthera aurea (A. Gray) Shinners