Geranium soboliferum Kom.

The name of Geranium soboliferum refers to its ability to produce soboles, that are underground stolons. Yeo (Hardy Geraniums, 108. 2002) cultivated this species and stated that this feature was not present in these plants. Among the studied material no trace of soboles was found. The stipules are usually longer than in G. dahuricum.

Perennials. Rootstock ± vertical, 8-9 mm in diam., not tuberculate, with a fascicle of long thickened roots. Stem 49-89 cm tall, erect, not rooting at nodes, with 0.2-0.5 mm retrorse appressed nonglandular trichomes. Stipules lanceolate, connate at least at base. Leaves opposite; petiole with 0.2-0.5 mm retrorse appressed nonglandular trichomes; leaf blade 4.1-9.5 cm, palmately cleft, ratio of main sinus/middle segment length = 0.89-0.96, pilose with appressed nonglandular trichomes; segments 5, rhombic, 1.6-4.4 mm wide at base, 8-18-lobed in distal half, ratio of second sinus/middle segment length = 0.3-0.58. Cymules solitary, 2-flowered; peduncle 4.7-10.4(-13.7) cm. Pedicel 1.1-4.1 cm, with 0.2-0.6 mm retrorse appressed or rarely patent nonglandular trichomes; bracteoles lanceolate. Sepals 7.3-10.8 mm, mucro 1.2-2.5 mm, ratio of mucro/sepal length = 0.13-0.26, outside with 0.2-0.4 mm antrorse appressed nonglandular trichomes, inside glabrous. Petals deep reddish purple, (1.3-)1.4-1.8(-2) cm, erect to patent, outside basally with trichomes, inside basal 1/3-1/2 with trichomes, margin basally ciliate, apex rounded. Staminal filaments purplish, lanceolate, base slightly dilated, abaxially pilose and proximal half ciliate, trichomes 0.2-0.6 mm; anthers bluish, 1.5-2.3 mm. Nectaries 5, hemispheric, with a tuft of trichomes at apex, abaxially glabrous. Stigma reddish. Fruit 2.8-3.5 cm, erect when immature; mericarps smooth, with a basal callus, with 0.1-0.7 mm ± patent nonglandular trichomes and sometimes apically with 0.7-1.1 mm patent glandular trichomes; rostrum 1.8-2.3 cm, with a 1.9-3.4 mm narrowed apex; stigmatic remains 5-6.7 mm. Seeds 2.3-2.6 mm. Fl. Jul-Aug, fr. Aug-Sep. 2n = 28.

Heilongjiang, Jilin [Japan, Korea, Russia (Far East)].

Broad-leaved forests, meadows; ca. 400 m.