20. Cardamine stenoloba Hemsley, J. Linn. Soc., Bot. 29: 303. 1892.
狭叶碎米荠 xia ye sui mi ji
Cardamine pratensis Linnaeus subsp. chinensis O. E. Schulz; Loxostemon stenolobus (Hemsley) Y. C. Lan & T. Y. Cheo.
Herbs perennial, 5-25 cm tall, slender, glabrous except for leaves. Rhizomes slender, stoloniferous. Stems simple, branched above, flexuous. Basal leaves not rosulate, often withered by anthesis; petiole 1-1.5 cm; terminal leaflet orbicular, 2-4 mm in diam., with a petiolule 1-4 mm, sparsely pilose, base rounded, margin entire or obscurely lobed; lateral lobes similar to terminal one. Middle and upper cauline leaves pinnatisect, margin scabrous with trichomes to 0.1 mm; petiole 3-8 mm, not auriculate at base; terminal lobe filiform, 1-2.5 cm × 0.4-0.7 mm, base attenuate and decurrent with adjacent lateral lobes, margin entire, apex acute, not mucronate; lateral lobes 1-3 pairs, sessile, decurrent, similar to terminal lobe but smaller. Racemes 2-8-flowered, rachis strongly flexuous. Pedicels of young fruit divaricate, 8-14 mm, slender, soon recurved, glabrous. Sepals ovate, 1.5-2 × 0.8-1 mm, glabrous, membranous at margin and apex. Petals white, obovate or broadly spatulate, 5-6 × 2.5-3 mm. Median filament pairs 2.5-3 mm, filiform; lateral pair 1.5-2 mm; anthers oblong, 0.5-0.6 mm. Median nectar glands oblong, to 0.5 mm. Ovules 8-12 per ovary. Fruit linear, 1.5-2.2 cm × ca. 1 mm; valves glabrous; style 1-1.5 mm. Seeds pale brown, oblong, ca. 1.8 × 0.8 mm, wingless.
* Shaanxi, Sichuan.
Cardamine stenoloba is known only from three collections, the syntypes A. Henry 8794 (listed as "8724" in the protologue) and Pratt 352 (both at K and mounted on the same sheet), and the type of C. pratensis subsp. chinensis (H. Biondi 439 at B). The species is here lectotypified on Pratt's collection. It is most closely related to C. elegantula J. D. Hooker & Thomson (from Bhutan, Nepal, and Sikkim), from which it is readily distinguished by having finely pinnatisect middle and upper cauline leaves with 1-3 pairs of filiform, basally decurrent, acute lateral lobes and well-developed median glands to 0.5 mm. By contrast, C. elegantula has compound leaves with 5-7 pairs of elliptic or oblong, petiolulate, apically mucronate lateral leaflets and obsolete median glands.
Cardamine stenoloba was treated in Loxostemon in both FRPS (pp. 239, 241) and Fl. Sichuan. (14: 111-112. 1999), but the species has filiform stamens and no bulbils, and the illustrations of L. stenolobus in these two floras in fact represent young plants of C. parviflora.