Gulf Coast camphor-daisy

Haplopappus phyllocephalus de Candolle in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 5: 347. 1836 (as Aplopappus); H. phyllocephalus var. megacephalus (Nash) Waterfall; Machaeranthera phyllocephala (de Candolle) Shinners; M. phyllocephala var. megacephala (Nash) Shinners; Sideranthus megacephalus (Nash) Small

Annuals or perennials, 10–70(–100) cm, herbaceous to suffrutescent. Leaf blades oblong to oblanceolate, mid-cauline (2.5–)4–13 mm wide. Heads essentially sessile, often surpassed by distal leaves that continue to very base of heads. Involucres (6–)10–15 × 12–30 mm. Phyllaries in 3–4 series, loose, subequal, apices erect to spreading, 1.3–1.7 mm wide, herbaceous. Ray florets 17–38; corollas 8.5–19 mm. Disc florets: corolla tubes longer than limbs. 2n = 12.

Flowering (Jul–)Sep–Dec (sporadically Feb–Jun). Sandy sites, along waterways, canal banks, dunes, beaches, salt flats; 0–10 m; Colo., Fla., La., Tex.; Mexico (Tamaulipas).

SELECTED REFERENCE

Jackson, R. C. and C. T. Dimas. 1981. Experimental evidence for systematic placement of the Haplopappus phyllocephalus complex (Compositae). Syst. Bot. 6: 8–14.