大花南芥 da hua nan jie

Arabis macrantha C. C. Yuan & T. Y. Cheo; A. pangiensis Watt.

Herbs perennial, 15-40 cm tall, often densely tomentose or pilose, with primarily short-stalked, stellate trichomes, these sometimes mixed with much fewer, simple or forked ones, rarely plants glabrescent and trichomes restricted primarily to leaf margins. Stems erect, often branched at base. Basal leaves rosulate; petiole 0.5-5 cm; leaf blade obovate-spatulate, oblong, elliptic, or oblanceolate, 1.5-5 × 0.5-1.5 cm, base attenuate, margin dentate or entire, apex obtuse or rounded. Middle cauline leaves sessile, oblong-linear, narrowly elliptic, or narrowly lanceolate, 1-4(-5.5) cm × 2-8 mm, base obtuse or auriculate, margin dentate or entire. Racemes ebracteate. Fruiting pedicels divaricate or ascending, (0.8-)1.2-2.4(-3) cm, slender, straight, glabrous. Sepals oblong, 3.5-5 × 1.2-1.8 mm, glabrous, lateral pair saccate. Petals white or pinkish, oblong or narrowly oblanceolate, 0.9-1.4 cm × 2-4 mm, apex obtuse. Filaments 5-8 mm; anthers oblong, 1-1.5 mm. Ovules 40-70 per ovary. Fruit 3-6 cm × 1-1.2 mm; valves with a prominent midvein extending full length, slightly torulose, glabrous; style 1-1.5 mm. Seeds brown, oblong, ca. 1.2 × 0.5 mm, uniseriate, narrowly winged apically. Fl. Apr-Jun, fr. May-Jul.

Grassy slopes, rock crevices, dry cliffs, stony pastures; 2400-3000 m. Sichuan, Yunnan [Kashmir, Pakistan].

Arabis bijuga, which was previously thought to be restricted to Kashmir and Pakistan, is recorded here for the first time from China. The records from Sichuan are based on Soulié 1493 (P) and the type collection of A. macrantha, Fang Wen-pei et al. 12402 (NAS, SZ); the record from Yunnan is based on Yü 8456 (BM), Forrest 20147 (E, US), and Forrest 16192 (E).

The type collection of Arabis bijuga is basically indistinguishable from those of A. macrantha and A. pangiensis except for being glabrescent (vs. moderately to densely tomentose). However, this difference alone does not justify the recognition of more than one species.