Viola hossei W. Becker

Herbs perennial, acaulescent. Rhizome 1-20 cm, 1.5-2.5 mm in diam., with brown remains of stipules at nodes. Stolon 15-20 cm, longest to 40 cm, slender, glabrous, producing adventitious roots. Leaves basal or alternate on stolon; stipules free, deep brown, linear-lanceolate, 7-15 mm, margin long fimbriate-dentate; petioles unequal in length, 2-9 cm, narrowly winged in upper part, puberulous or glabrescent; leaf blade abaxially greenish, adaxially deep green or dark green, triangular-ovate or oblong-ovate, 2-5 × 1.5-3 cm, usually broadest near base, both surfaces glabrous or sparsely white puberulous and dotlike brown glandular, base deeply cordate, margin shallowly serrate or shallowly crenate, glandular at apices of teeth, apex long acuminate. Flowers violet to light purple or white; pedicels usually not exceeding leaves, 2-bracteolate at or slightly above middle; bracteoles opposite, rarely alternate, 3-8 mm. Sepals linear-lanceolate, 5-6 mm, apex acute; appendages very short, only ca. 0.5 mm, 3-veined, dotlike rusty glandular, margin membranous, apex truncate. Petals oblong-ovate, 8-10 × ca. 3 mm, lateral ones glabrous, anterior one shorter, ca. 7 mm (spur included); spur saccate, short, ca. 1.5 mm, usually twice as long as calycine appendages; spur of 2 anterior stamens short, wide, shortly angular, usually subequaling anthers. Ovary ovoid-globose; styles clavate, base slightly geniculate, gradually thickened upward; stigmas thickened and conspicuously margined on lateral sides, margin spreading, shortly beaked in front, beak erect, with a smaller stigma hole at tip. Capsule ellipsoid, small, 5-7 mm, dotlike brown rusty glandular. Seeds globose, small, ca. 0.5 mm in diam. Fl. spring-summer, fr. summer-autumn. 2n = 46.

Guangxi, Guizhou, Hainan, S Yunnan [Indonesia, Malaysia, Myanmar, Thailand, Vietnam].

Shaded forests, forest margins, streamsides, rock crevices along streamsides; below 2400 m.

Viola hossei W. Becker.

Hoa tím Sumatra (danh pháp khoa học: Viola sumatrana) là một loài thực vật có hoa trong họ Hoa tím. Loài này được Miq. miêu tả khoa học đầu tiên năm 1861.