Plant terrestrial; evergreen; with very short rhizomes from which upright stems arise, monoecious. Stems green to reddish brown, to 110 cm long, 19 mm across, glabrous. Rhizomes greenish or reddish, to ___ cm long, ___ mm across, glabrous. Stipules caducous, narrowly deltoid to lanceolate, apex acuminate, margins entire, to 24 mm long, 19 mm wide, glabrous. Leaves many, upper surface green, lower surface greenish or reddish, asymmetric, lanceolate to broadly lanceolate, undivided, apex acuminate to cuspidate, base obtuse, margins irregularly denticulate or serrulate, 9-24 cm long, 3.5-8 cm wide, sparsely hispidous; venation palmate-pinnate; petioles, 3-12 mm long, to 5 mm across, glabrous. Inflorescences arise from stem, glabrous; peduncles (inflorescence axis) strongly reduced, ca. 2 cm long, 1.6 mm across, pendent; pedicel pendent. Bracts caducous, apex mucronate to acuminate, margins entire, to 19 mm long, 12 mm wide, glabrous. Staminate flowers: tepals 4, white, crateriformis, apex obtuse, glabrous, outer two broadly ovate to subglobose, 8-13 mm long, 6-12 mm wide, inner two elliptic, 7-11 mm long, 4-6 mm wide; androecium actinomorphic; filaments free, nearly equal in length, 0.8-1.4 mm long; anthers (number), yellowish, clavate, longer than filaments, 1.7-2.4 mm long, 0.4-0.6 mm across. Pistillate flowers: tepals 6, white, nearly equal, broadly elliptic to rotund, 7-12 mm long, 5-9 mm wide, glabrous; ovary green when blooming, inferior; styles 3, yellowish, free, forked once, yellowish, 4.9-5.4 mm long;; stigmas in a band and spiraled. Fruits berry-like, indehiscence, pendent, green, broadly ellipsoid, ___ mm long, 17-18 mm across, glabrous; indistinctly 3-ridged to conspicuously 3-horned; shallowly 3-grooved between locules; beaks 0-3 mm long. locules 3, axile placentation, placental branches 2 per locule.

TAIPEI: Shihting-Huangtitien, Hsu & Lin 41 (HAST); Huangtitien, Yang 43 (TAI); Hsiaoyii, Chen 108 (HAST); Wulai, Peng 4688, 8355, 1000 (HAST), Sasaki s.n. Aug. 28, 1927 (TAIF), Jeng 2548 (TAI), Sasaki s.n. May 25, 1932 (TAI), Mutuda s.n. Jul. 25, 1918 (TAIF), Lai s.n. Mar. 31, 1971 (NTUF), Chuang 2310 (TAI); Fushan, Nakamuna 638 (TAI), Huang 1277 (TAI); Tatungshan, Kuo 5581 (TAI); Leikungpo-Hsiaoketou, Peng et al. 11965 (HAST), Peng & Hu 12271 (HAST); Kankou, Kao 7904(TAI), Sasaki s.n. Nov. 1, 1932 (TAI); Chengpai-Peichatienshan, Peng 8611 (HAST).
ILAN: Taipingshan, Suzuki s.n., Aug. 15, 1928 (TAI).
TAOYUAN: Peichatienshan, Peng 10132 (HAST), Mori s.n. May 25, 1908 (TAIF); Chiaopanshan, Hayata s.n. Jan. 1912 (TAIF).
HSINCHU: Wuchihshan, Kawakami 1296 (Syntype of B. aptera Hay., TAIF).
MIAOLI: Tahu, Kawakami et al. 57 (TAIF); Sanyii, Susuki s.n. Jul. 28, 1940 (TAI).
TAICHUNG: Tungshih Forest Station, Chen 393 (HAST); Pahsiehshan, Sasaki s.n. Nov. 23, 1922 (TAIF); Lineng, Sasaki s.n. Nov. 21, 1922 (TAI); Taichung, Suzuki s.n. Jul. 17, 1936 (TAIF).
NANTOU: Shuili, Peng & Chen 11952; Huisun Forest Station, Peng 12232 (HAST), Ou 8511 (TCF), Ying 1220 (NTUF); Meiyuan, Sasaki s.n. Nov. 29, 1922 (TAIF); Touchuang, Shimada 14181 (TAIF); Guandaushi, Liu s.n. Sep. 18, 1969 (TCF); Sun-Moon Lake, Ying 4991 (NTUF); Citou, Liu s.n. Apr. 1, 1971 (NTUF).
HUALIEN: Fuyuan Butterfly Valley, Peng & Chen 11653 (HAST); Tatung-Tali, Chen 161 (HAST); Lienhuachih-Taomikengka, Mori s.n. Jul. 6, 1936 (TAI).

Tebbitt, M.C.2003. Taxonomy of Begonia longifolia Blume (Begoniaceae) and related species. Brittonia 55(1): 19–29.

Stolons: absent

Stipules: caducous

Stipules: shape: triangular, narrowly triangular

Stipules: apex: acuminate

Stipules: margin: entire

Stipules: length (mm): 24 mm

Stipules: width (mm): 19 mm

Stipules: indumentum: glabrous

Leaves: shape: lanceolate

Leaves: apex: acuminate

Leaves: margin: denticulate, serrulate

Leaves: length (cm): 9-24 cm

Leaves: width (cm): 3.6-8 cm

Leaves: indumentum: glabrous, scaberulous

Venation: palmate-pinnate

Petioles: length (cm): 3-12 cm

Petioles: diameter (mm): 5 mm

Petioles: indumentum: glabrous

Bracts: caducous

Bracts: apex: mucronate, acuminate

Bracts: margin: entire

Bracts: length (mm): 19 mm

Bracts: width (mm): 12 mm

Bracts: indumentum: glabrous

Peduncles:: pendulous

Peduncles: length (cm): 2 cm

Peduncles: diameter (mm): 2 mm

Flowers: color: white

Male flower petals: number: four

Outer 2 tepals of male flowers: shape: broadly ovate

Outer 2 tepals of male flowers: length (mm): 8-13 mm

Outer 2 tepals of male flowers: width (mm): 6-12 mm

Inner 2 tepals of male flowers: shape: elliptic

Inner 2 tepals of male flowers: length (mm): 6-11 mm

Inner 2 tepals of male flowers: width (mm): 4-6 mm

Stamens: shape: clavate

Anthers: length (mm): 1.7-2.4 mm

Anthers: diameter (mm): 0.4-0.6 mm

Filaments: shorter than anthers

Filaments: length (mm): 0.8-1.4 mm

Female flower tepals: number: six

Female flower tepals: equality of size: equal, subequal

The largest tepals of female flowers: shape:: broadly obovate

Styles: number: three

Styles: length (mm): 4.9-5.4 mm

Ovary: shape: ellipsoid

Locules number: three

Fruits: typ: baccate

Fruits: wings: wingless

Seeds: shape: broadly ellipsoid

Seeds: length (mm): 0.25-0.28 mm

Seeds: diameter (mm): 0.18-0.21 mm

Seed apex: shape: rotund

Seed micropylar end: constricted

Chrosome numer 2n=: 22

Elevation (m): 50-2200 m

Distribution: Taipei, Taoyuan, Ilan, Hsinchu, Miaoli, Taichung, Nantou, Hualien

Plant: growth form: terrestrial

Phenology: evergreen

Stems: habit: with very short(or without) rhizomes from which upright stem arise