Plant terrestrial or epipetric; evergreen; with long creeping rhizomes from which upright stems arise, monoecious.
Stems 6-45 cm long, 4(-12) mm across, glaborus.
Rhizomes ___ cm long, 12 mm across, glabrous.
Stipules caducous, broadly ovate or triangular, apex apiculate, margins entire, to 8(-17) mm long, 8(-15) mm wide, glabrous.
Leaves many, basal and cauline, herbaceous, asymmetric, broadly lanceolate to ovate, shallowly lobed to nearly undivided, apex acuminate to apiculate, base cordate, margins irregularly denticulate or serrulate, 6-14(25) cm long, 2.5-6.7(11.5) cm wide, sparingly scaberulous on both surfaces; venation palmate-pinnate; petioles 1.5-26(35) cm long, to 6 mm across, glabrous or sparingly pilose.
Inflorescences arise from stem, to 5 cm long, glabrous; peduncles (inflorescence axis) 3 cm long, 1.5 mm across, erect to pendent.
Bracts caducous, lanceolate to ovate, apex mucronate, margins ciliate, to 8(-17) mm long, 3(-12) mm wide, glabrous.
Flowers of both sexes white or pinkish, glabrous.
Staminate flowers: tepals 4, outer two broadly ovate to very broadly ovate, 4-9 mm long, 4-10 mm wide, inner two broadly elliptic, 4-8 mm long, 3-6 mm wide; androecium actinomorphic; stemans 71-96, golf-club shaped, yellow, filaments free, 0.3-0.5 mm long; anthers obovate, 0.8-1.2 mm long, 0.4-0.5 mm across.
Pistillate flowers: tepals 5 or 6, obovate to broadly obovate, unequal, the largest to 18 mm long, 15 mm wide, the smallest to 12 mm long, 6 mm wide; ovary greenish when blooming, inferior, glabrous; styles 2 or 3, yellow, free, forked once, 2.5-3.5 mm long; stigmas in a band and spiraled.
Fruits capsular, dehiscence, nodding, trigonous, unequally 3-winged, abaxial wing nearly triangular, 5-7 mm long, 5-7mm wide, lateral wings 1.8-3mm long, 7-10 mm wide; locules 2, axile placentation, placental branches 2 per locule.
TAIPEI: Hsichih, Peng 16320 (HAST); Wulai-Hsiayi, Peng 14804, Peng 15100 (CAS, HAST, TAIF, TNM, OOM), Peng 15105, 16278 (HAST), Leu 711 (2 sheets, HAST), Leu 1870, 1871 (HAST), Liu 132, 133 (HAST).
Presently know only in Taipei Hsien, northern Taiwan, scattered for nearly 20 km along a mountain trail on west side of Nanshih River valley at ca. 200-500m elevation in Wulai. It is also found disjunctly in Hsichih, ca. 25 km northeast of Wulai.
Peng, C.-I. & C.-Y. Sue. 2000. Begonia ×taipeiensis (Begoniaceae), a new natural hybrid in Taiwan. Bot. Bull. Acad. Sin. 41(2): 151-158.
Peng, C.-I & T.-Y. Chiang. 2000. Molecular confirmation of unidirectional hybridization in Begonia ×taipeiensis Peng (Begoniaceae) from Taiwan. Ann. Missouri Bot. Gard. 87: 273-285.
Chiang, T.-Y., K.-H. Hong & C.-I Peng. 2001. Experimental hybridization reveals biased inheritance of the internal transcribed spacer of the nuclear ribosomal DNA in Begonia ×taipeiensis. J. Plant Res. 114: 343-351.
Stipules: shape: broadly ovate, triangular
Stipules: apex: apiculate
Stipules: margin: entire
Stipules: length (mm): 8-17 mm
Stipules: width (mm): 8-15 mm
Stipules: indumentum: glabrous
Leaves: shape: ovate, narrowly ovate, broadly lanceolate
Leaves: apex: acuminate
Leaves: margin: denticulate, serrulate
Leaves: length (cm): 14 (6-25) cm
Leaves: width (cm): 7 (2.5-11.5) cm
Leaves: indumentum: scaberulous
Veins: number: 5-8
Petioles: length (cm): 1.5-35 cm
Petioles: diameter (mm): 6 mm
Petioles: indumentum: glabrous, pilose
Bracts: shape: ovate, lanceolate
Bracts: apex: mucronate
Bracts: margin: ciliate
Bracts: length (mm): 8-17 mm
Bracts: width (mm): 3-12 mm
Bracts: indumentum: glabrous
Inflorescence: length (cm): 5 cm
Peduncles: length (cm): 3 cm
Peduncles: diameter (mm): 2 mm
Flowers: color: white, pinkish
Male flower petals: number: four
Outer 2 tepals of male flowers: shape: broadly ovate
Outer 2 tepals of male flowers: length (mm): 4-9 mm
Outer 2 tepals of male flowers: width (mm): 4-10 mm
Inner 2 tepals of male flowers: shape: elliptic
Inner 2 tepals of male flowers: length (mm): 4-8 mm
Inner 2 tepals of male flowers: width (mm): 3-6 mm
Stamens: number: 71-96
Stamens: shape: golf-club shaped
Anthers: shape: obovoid
Anthers: length (mm): 0.8-1.2 mm
Anthers: diameter (mm): 0.4-0.5 mm
Filaments: shorter than anthers
Filaments: length (mm): 0.3-0.5 mm
Female flower tepals: number: five, six
Female flower tepals: equality of size: unequal
The largest tepals of female flowers: shape:: broadly obovate
The largest tepals of female flowers: length (mm): 18 mm
The largest tepals of female flowers: width (mm): 15 mm
The smallest tepals of female flowers: shape: obovate
The smallest tepals of female flowers: length (mm): 12 mm
The smallest tepals of female flowers: width (mm): 6 mm
Styles: number: two, three
Locules number: two
Abaxil wing of fruits: shape: triangular
Abaxil wing of fruits: length (mm): 5-7 mm
Abaxil wing of fruits: width (mm): 5-7 mm
Lateral wings of fruits: length (mm): 1.8-3 mm
Lateral wings of fruits: width (mm): 7-10 mm
Chrosome numer 2n=: 41
Elevation (m): 200-500 m
Plant: growth form: terrestrial, epipetric
Stems: habit: with long ascentant rhizomes from which upright stems arise