Perennials. Rootstock ± horizontal, short, 7.1-10.2 mm in diam., not tuberculate, with many fibrous long roots. Stem 9-48 cm tall, erect, not rooting at nodes, with 0.2-0.4 mm retrorse appressed nonglandular trichomes and rarely 0.3-0.4 mm patent glandular trichomes. Stipules lanceolate, distinct. Leaves opposite; petiole with 0.2-0.5 mm retrorse appressed nonglandular trichomes and sometimes 0.4-0.5 mm patent glandular trichomes; leaf blade 1.7-6.2 cm, palmately cleft, ratio of main sinus/middle segment length = 0.72-0.84, pilose with appressed nonglandular trichomes; segments 5, rhombic, 2.5-8.8 mm wide at base, 6-15-lobed in distal half, ratio of second sinus/middle segment length = 0.19-0.31. Cymules solitary, 2-flowered; peduncle 4.1-14(-23) cm. Pedicel 0.1-8.3 cm, with 0.2-0.5 mm retrorse uncinate nonglandular trichomes and usually 0.2-0.6 mm patent glandular trichomes; bracteoles lanceolate. Sepals (8.4-)9-10.3(-11.3) mm, mucro 0.7-1.9(-2.5) mm, ratio of mucro/sepal length = 0.08-0.24, outside with 0.2-0.6 mm antrorse ± appressed nonglandular trichomes and usually 0.3-0.5 mm patent glandular trichomes, inside glabrous. Petals purplish, (1.6-)1.8-2.8 cm, erect to patent, both surfaces glabrous, margin basally ciliate, apex emarginate with a 0.3-1.4 mm notch. Staminal filaments pinkish, lanceolate with a broadly triangular base and an abruptly narrowed apex, glabrous except proximal half with some 0.1-0.3 mm cilia; anthers brownish when dry, 2.1-2.9 mm. Nectaries 5, hemispheric, abaxially glabrous, apex with a tuft of trichomes. Stigma purple when dry. Fruit 3.4-4 cm, erect when immature, with white hyaline glandular trichomes and pubescences. Seeds 3-3.5 × 1.4-1.8 mm. Fl. Jul-Aug, fr. Aug-Sep.