Perennial herb, 0.15–0.5 m tall, glabrous, erect to ascending, not rooting, branching at base then not below inflorescence, basal sterile shoots erect. Stems not or scarcely glaucous, with ± numerous, not or scarcely prominent scattered black glandular dots throughout; internodes 20–40 mm, exceeding leaves. Leaves sessile, spreading, sometimes glaucous; lamina (main stem) 10–30 × 1–5 mm, linear, apex retuse, margin revolute, base cuneate, 1-veined or occasionally with 1–2 pairs of lateral branches, with laminar glands pale, small, ± numerous and often black, and a larger subapical black gland beneath, marginal glands dense; lamina (axillary and sterile shoots) smaller, otherwise similar. Inflorescence ∞-flowered, from 6–11 nodes, narrowly to broadly cylindric, rather lax, 5–18(–23) mm long, with lateral cymules 1–7-flowered, without flowering branches below; bracts and bracteoles reduced foliage leaves, retuse to rounded. Flowers c. 15–25 mm in diam., with petals deflexed after flowering; buds globose. Sepals subequal or equal, c. ¼ united, not imbricate, 1–3 × 0.7– 1.5 mm, oblong, obtuse to rounded; veins 3; margin distally with regular small, sessile or subsessile, globose black glands or rarely subentire, eglandular; laminar glands 2, pale or usually black, linear. Petals bright? yellow, not red-tinged, 7–10 × 4–6 mm, 3–7 × sepals, obovate, long-unguiculate, rounded, entire or rarely with 1–5 sessile marginal black glands; laminar glands pale or usually some or nearly all black, few to numerous, striiform to punctiform. Stamens c. 60, longest c.7–9 mm; filaments not red-tinged. Ovary 2.5–3 × 1.5–2 mm, ovoid-acuminate; styles 3–4 mm, 1.2–1.3 × ovary. Capsule 5–7 × 3–4.5 mm, ovoid-pyramidal, scarcely rostrate. Seeds reddish brown, c. 2 mm long.
Steppe, hillsides and field margins on calcareous soil; 300–1150 m.
Northern Syria., south & east Turkey, north Iraq.
The retuse leaf apex, nearly always with an abaxial black gland, makes H. retusum unmistakeable. Like 14. H. libanoticum, it would seem to be a derivative of 13. H. hedgei but with a more eastern distribution.