Thesium subaphyllum Engl.

Annual herb with a small taproot; stems green to grey-green, 1(–few) from a taproot, erect, 0.3–1 m tall, virgately branched above, nearly leafless; ribs expanding into flattened wings up to ± 1 mm broad and terminating in the midribs of the bracts.. Leaves: developed leaves only 2 near base of stem, opposite, linear, 20–30x1–1.4 mm; cauline leaves alternate, reduced to scales, closely appressed, lanceolate, 1–2x0.4–0.8 mm, acuminate, midrib strongly raised beneath.. Flowers solitary in axils of bracts, sessile, 10–50 in lax spikes, laxly panicled; bracts linear-lanceolate, 1–1.5x0.4–0.6 mm, acuminate; bracteoles 2, similar but smaller than bracts.. Perianth yellowish, white inside; tube 0.5–1 mm long, with glands lacking or no more than small swellings between the lobes; lobes triangular, 0.6–1.2 mm long, subacute, margins inflexed, membranous, ± erose.. Stamens inserted at base of lobes; filaments 0.2–0.5 mm long, almost hidden by anthers, anthers 0.6–0.8 mm long.. Style 0.8–1.6 mm long; stigma reaching top of anthers.. Fruit pallid, ellipsoid-globose to globose, 3–4 mm long, 2.5–4 mm in diameter, strongly ribbed and reticulate, the reticulations rather more strongly raised than the ribs, dendroid-ruminate.. Fig. 1/1–3 (page 4).