27. Geranium donianum Sweet, Geraniaceae. 4: ad t. 338. 1827.
长根老鹳草 chang gen lao guan cao
Geranium stapfianum Handel-Mazzetti; G. stenorrhizum Stapf.
Perennials. Rootstock ± horizontal, 1.4-4.1(-5.7) mm in diam., not tuberculate, with thickened roots along rootstock. Stem 8-20(-40) cm tall, erect, not rooting at nodes, with 0.2-0.6 mm retrorse to appressed nonglandular trichomes. Stipules lanceolate, distinct. Leaves opposite; petiole with 0.3-0.9 mm retrorse to appressed nonglandular trichomes; leaf blade 1.4-3.3 cm, palmately cleft, ratio of main sinus/middle segment length = 0.76-0.89, pilose with appressed nonglandular trichomes; segments 5, rhombic to obtriangular, 1.5-3 mm wide at base, 3-9-lobed in distal half, ratio of second sinus/middle segment length = 0.23-0.44. Cymules solitary, 2-flowered; peduncle (2.6-)3-10.3(-11) cm. Pedicel 1.2-4.7(-6.9) cm, with 0.2-0.6 mm retrorse to appressed nonglandular trichomes; bracteoles linear-lanceolate. Sepals (6.9-)7.5-9.6 mm, mucro (0.4-)0.6-1.2 mm, ratio of mucro/sepal length = 0.04-0.15, outside with 0.3-1.2 mm antrorse to patent nonglandular trichomes, inside almost glabrous. Petals deep purplish, (1.4-)1.5-2.3 cm, erect to patent, margin basally ciliate, apex emarginate with a 0.7-4.5 mm notch. Staminal filaments dark red distally but paler at base, lanceolate, abaxially pilose and proximal half ciliate, trichomes 0.4-0.8(-1.2) mm; anthers reddish, 2-2.9 mm. Nectaries 5, hemispheric, abaxially glabrous, apex with a tuft of trichomes. Stigma dark red. Fruit 2.2-2.6 cm, erect when immature; mericarps smooth, with a basal callus, with 0.4-0.6 mm erect to patent nonglandular trichomes; rostrum 1.6-1.9 cm, with a 2.7-4.1 mm narrowed apex; stigmatic remains 2.8-4.5 mm. Seeds 2.2-2.3 mm. Fl. Jul-Aug, fr. Aug-Sep.
Scrub, alpine meadows; 2500-4500 m. S Gansu, SE Qinghai, W Sichuan, E Xizang, NW Yunnan [Bhutan, India (Sikkim), Nepal].
Geranium stapfianum is considered by some authors to be a different species endemic to Sichuan and Yunnan, G. donianum thus being a Himalayan plant. For supporting such a distinction, a more robust rootstock and habit is attributed to western specimens of G. donianum. However, a great variability in these features has been observed along the whole area of G. donianum, and this does not support such a division.
The rootstock rarely could have some thickened areas that are not clearly differentiated, which should not be mistaken with the tubercles of Geranium pylzowianum.