92. Aphragmus Andrzejowski ex de Candolle, Prodr. 1: 209. 1824.
寒原荠属 han yuan ji shu
Oreas Chamisso & Schlechtendal; Orobium Reichenbach; Staintoniella H. Hara.
Herbs perennial, with thick caudex covered with petiolar remains of previous years, sometimes with slender rhizomes. Trichomes eglandular, simple or forked, less than 0.1 mm. Stems erect or ascending, branched basally, often minutely puberulent. Basal leaves petiolate, rosulate, simple, entire. Cauline leaves petiolate or sessile, base cuneate or attenuate, not auriculate. Racemes few to several flowered, bracteate throughout, slightly elongated or not in fruit. Fruiting pedicels slender, erect, ascending, divaricate, sometimes recurved, puberulent adaxially. Sepals oblong, base of lateral pair not saccate. Petals white, pink, or purple; blade broadly obovate or spatulate, apex obtuse or rounded; claw subequaling sepals. Stamens 6, slightly tetradynamous; filaments dilated or not at base; anthers obtuse at apex. Nectar glands confluent and subtending bases of stamens. Fruit dehiscent silicles or siliques, ovate, elliptic, lanceolate, rarely linear, latiseptate; valves with an obscure or distinct midvein, smooth; replum flattened basally; septum complete and membranous, or absent; style obsolete or rarely to 2 mm; stigma capitate, entire. Seeds uniseriate or biseriate, wingless, oblong or ovoid, plump, on filiform funicles often longer than seeds; seed coat minutely reticulate, not mucilaginous when wetted; cotyledons incumbent.
Five species: C Asia, Himalayas, North America; one species in China.