密序山萮菜 mi xu shan yu cai

Braya heterophylla W. W. Smith, Notes Roy. Bot. Gard. Edinburgh 11: 201. 1919; Eutrema compactum O. E. Schulz; E. edwardsii R. Brown var. heterophyllum (W. W. Smith) W. T. Wang; E. obliquum K. C. Kuan & Z. X. An.

Herbs 2-15(-25) cm tall, glabrous throughout or rarely puberulent, with a caudex and fleshy root. Stems erect, simple, often few from caudex. Basal leaves rosulate, somewhat fleshy; petiole (0.5-)1-5.5(-7.5) cm; leaf blade ovate, suborbicular, lanceolate, or rhombic, (0.3-)0.5-2(-2.5) cm × (2-)4-10(-15) mm, base cordate, truncate, or cuneate, sometimes distinctly oblique, margin entire, apex obtuse or subacute. Middle cauline leaves lanceolate, ovate, or linear-lanceolate, 0.7-2.5(-3) cm × 2-9 mm, pinnately veined, sessile, base cuneate, margin entire, apex subacute. Infructescence compact, subumbellate or short racemes, little or not expanded in fruit, 0.2-2(-3.5) cm. Fruiting pedicels divaricate or slightly reflexed, 1-4(-5) mm. Sepals ovate, 1.5-2 × ca. 1 mm, persistent through fruit maturity. Petals white, spatulate, 2-3.5 × 1-1.7 mm. Filaments white, 1-2 mm, slightly dilated at base; anthers ovate, 0.2-0.3 mm. Ovules 4-10 per ovary. Fruit linear or oblong, (4-)5-10(-12) × 1.5-2 mm, slightly 4-angled, not torulose; valves cuneate at both ends, with a prominent midvein; gynophore to 0.5 mm; septum mostly perforate; style obsolete to 0.6 mm. Seeds oblong, plump, 1.5-2 × ca. 1 mm. Fl. Jun-Jul, fr. Jul-Aug.

Alpine meadows, scree, grassy slopes, near glaciers, Kobresia turf, alpine mats, sandstone ridges; 2500-5400 m. Gansu, Hebei, Qinghai, Shaanxi, Sichuan, Xinjiang, Xizang, Yunnan [Bhutan, Kazakhstan, Kyrgyzstan, Nepal, Tajikistan].

The records of Eutrema edwardsii R. Brown from China (e.g., in FRPS) and C Asia are based on misidentified plants of E. heterophyllum. The former species has lax, racemose infructescences to 18 cm, fruit appressed to the rachis, with erect to erect-ascending fruiting pedicels, and readily caducous sepals. By contrast, E. heterophyllum has compact, umbellate or shortly racemose infructescences rarely to 3.5 cm, nonappressed fruit, with divaricate or reflexed fruiting pedicels, and sepals often persisting well after fruit maturity. The record and illustration of E. edwardsii from Xinjiang in Fl. Xinjiang. (2(2): 204. 1995) are based on misidentified plants of Taphrospermum altaicum.