陕西老鹳草 shan xi lao guan cao

Geranium retectum Yeo.

Perennials. Rootstock ± horizontal, 1-1.1 cm in diam., not tuberculate, with many fibrous roots. Stem 80-85 cm tall, erect, not rooting at nodes, with 0.3-0.4 mm patent to retrorse nonglandular trichomes. Stipules lanceolate, connate at least at base. Leaves opposite; petiole with 0.2-0.5 mm patent nonglandular trichomes and sometimes 0.8-1.1 mm patent glandular trichomes; leaf blade 9-10.9 cm, palmately cleft, ratio of main sinus/middle segment length = 0.76-0.84, pilose with appressed nonglandular trichomes; segments 5 or 7, rhombic, 1.3-2 cm wide at base, 17-21-lobed in distal half, ratio of second sinus/middle segment length = 0.05-0.18. Cymules solitary or in aggregates at apex of each branch, 2-flowered; peduncle 1.4-9.5 cm. Pedicel 1.8-2.6 cm, with 0.3-0.5 mm patent nonglandular trichomes and 0.4-1.9 mm patent glandular trichomes; bracteoles linear-lanceolate. Sepals 7.2-7.8 mm, mucro 0.4-1.5 mm, ratio of mucro/sepal length = 0.05-0.18, outside with 0.3-0.4 mm antrorse ± appressed nonglandular trichomes and 0.4-1.6 mm patent glandular trichomes, inside glabrous. Petals whitish, 7.3-8.6 mm, reflexed, both surfaces glabrous, margin basally with a dense tuft of trichomes, apex rounded. Staminal filaments reddish, lanceolate, abaxially sparsely pilose and proximal half ciliate, trichomes 2.1-2.9 mm; anthers bluish, 2.4-2.7 mm. Nectaries 5, hemispheric, abaxially glabrous, apex with a tuft of trichomes. Stigma green. Fruit 2.4-2.9 cm, erect when immature; mericarps smooth, with a basal callus, with 0.5-0.7 mm ± patent nonglandular trichomes and 0.3-0.9 mm patent glandular trichomes; rostrum 1.8-2.2 cm, with a 5-6 mm narrowed apex; stigmatic remains 1.7-1.8 mm. Seeds 1.9-2 mm. Fl. Jun-Jul, fr. Jul-Aug.

● Secondary forests, meadows; 1800-2800 m. Shaanxi, N Sichuan.

This species resembles Geranium platyanthum at first sight by the leaf aspect, long trichomes of staminal filaments, and cymules partially in aggregates at the top of each branch. However, G. shensianum has reflexed and shorter petals, nectaries with trichomes, and connate stipules, which are never present in the former.