BEGONIACEAE 1. BEGONIA Linnaeus, Sp. Pl. 2: 1056. 1753.

184
BEGONIACEAE
sule pendulous, clavate, trigonous, 4–5 cm × 5–6 mm, wingless.
Fl. Nov–Dec. 2n = 20*.
Broad-leaved forests or scrubby vegetation, on forest floor with
abundant leaf litter and humus; 100–200 m. SE Yunnan (Hekou) [Vietnam].
89. Begonia longifolia Blume, Catalogus, 102. 1823.
粗 喙 秋 海 棠 cu hui qiu hai tang
Begonia aptera Hayata (1911), not Blume (1827), nor
Roxburgh (1832), nor Decaisne (1834); B. crassirostris Irmscher;
B. hayatae Gagnepain.
Herbs, erect. Rhizomes short, stout. Stems 0.5–1.5 m tall,
well branched. Leaves cauline; stipules caducous, narrowly to
broadly ovate, to 2.4 × 1.9 cm, glabrous, apex acuminate; petiole
8–15 cm, glabrous or subglabrous; blade lanceolate to
broadly lanceolate, asymmetric, 8.5–29 × 3.4–11 cm, glabrous
or subglabrous, venation palmate-pinnate, 7–10-veined, base
oblique, cordate, margin remotely and irregularly denticulate.
Inflorescences strongly reduced, to 5 cm, pendulous; bracts
caducous, ovate to narrowly triangular, to 1.9 × 1.2 cm, thickly
papery, glabrous, margin entire, apex mucronate to acuminate.
Staminate flowers: pedicel 5–12 mm; tepals 4, white, outer 2
oblong to very broadly ovate, 0.9–1.3 cm × 5–10 mm, glabrous,
inner 2 elliptic, 0.6–1.5 cm × 4–8.2 mm; stamens 49–93; filaments
free, 0.7–2.5 mm; anthers lorate to broadly lorate, 1.7–
2.6 mm, apex emarginate. Pistillate flowers: pedicel 5–12 mm;
tepals 6, white, subequal, broadly elliptic to orbicular, 7–12 ×
5–9 mm; ovary glabrous, 3-loculed; placentae axile, bilamellate;
styles 3, fused at base; stigmas 2-cleft, spiraled. Capsule
pendulous, subglobose, 1.1–1.8 cm in diam., wingless or 3-
horned. Fl. Apr–May, fr. Jul. 2n = 22*.
Forests, shaded moist environments; 200–2200 m. Fujian, Guangdong,
Guangxi, Guizhou, Hainan, Hunan, Jiangxi, Taiwan, Yunnan
[Bhutan, NE India, Indonesia, Laos, Malaysia, Myanmar, Thailand,
Vietnam].
Nearly all species of Begonia are very narrowly distributed. Begonia
longifolia is probably the most widespread species in the genus. It
resembles B. acetosella when sterile, differing by being monoecious,
having a 3-loculed ovary, 6-tepaled pistillate flowers, and a remotely
denticulate leaf margin.
90. Begonia longistyla Y. M. Shui & W. H. Chen, Acta Bot.
Yunnan. 27: 367. 2005.
长 柱 秋 海 棠 chang zhu qiu hai tang
Herbs, rhizomatous. Rhizomes 7–10 cm × 2–4 mm,
sparsely hairy. Leaves all basal; stipules generally persistent,
reflexed, triangular; petiole 3–5 cm, densely strigose; blade
ovate, 6–10 × 4–6 cm, papery, rugose, abaxially densely hairy
on veins, adaxially densely tuberculate based pilose-setulose,
base obliquely deeply cordate, margin serrulate and ciliate, apex
obtuse. Inflorescences with 20–40 flowers in a dichasial cyme;
peduncle 4–8 cm, glabrous; bracts ovate, apex mucronate. Staminate
flowers: pedicels 7–8 mm, glabrous; bracteoles ovate, 2–3
× 1–1.5 mm, apex obtuse; tepals 4, glabrous, outer 2 green,
orbicular, 4–5 mm in diam., inner 2 greenish, obovate, 4.5–5 ×
3–3.5 mm; stamens numerous; filaments fused up to half from
base; anthers obovoid, 0.3–0.4 × 0.3–0.4 mm, apex emarginate.
Pistillate flowers: tepals 3, glabrous; ovary coniform, 7–8 × 3–4
mm, glabrous, 3-winged, apex with beak 1.5–2 mm, 1-loculed
with parietal placentation; styles 3, usually fused up to half
from base. Capsule nodding, ovate, 6–7 × 3–4 mm, with 3 persistent
styles; wings 3, subequal, lunate, glabrous. Fl. Feb–Jun,
fr. from Apr–Jun.
● Limestone slopes in dense broad-leaved forests, at streamsides;
200–300 m. Yunnan (Gejiu, Hekou).
91. Begonia lukuana Y. C. Liu & C. H. Ou, Bull. Exp. Forest
Natl. Chung Hsing Univ. 4: 6. 1982.
鹿 谷 秋 海 棠 lu gu qiu hai tang
Herbs, erect. Rhizomes short. Stems to 45–90 cm tall, glabrous.
Leaves all cauline; stipules caducous, narrowly ovate to
ovate, to 2.8 × 2 cm; petiole 6–26 cm, glabrous; blade abaxially
purple-red, adaxially usually dark green, lanceolate to narrowly
ovate, asymmetric, 9–33 × 5–14 cm, remotely scaberulous,
venation palmately-pinnate, 7–10-veined, base oblique, cordate,
margin irregularly serrulate, apex acuminate to cuspidate. Inflorescences
glabrous, 6–13 cm; peduncle to 9 cm; bracts caducous,
narrowly ovate, to 2.4 × 1.5 cm, glabrous. Staminate flowers:
tepals 4, white or pinkish, outer 2 obovate to very broadly
ovate, 0.7–1.5 cm × 6–13 mm, inner 2 oblanceolate to narrowly
obovate, 0.6–1.4 cm × 5–11 mm; stamens 64–89; filaments
1.2–1.9 mm; anthers narrowly oblong, 1.9–2.2 mm. Pistillate
flowers: tepals 5(or 6), white or pinkish, glabrous, unequal to
subequal, narrowly obovate to broadly ovate, largest 0.8–1.4 ×
0.7–1.3 cm, smallest 7–12 × 3–7 mm; ovary glabrous, 3-loculed;
placentae axile, bilamellate; styles 3, fused at base; stigmas
2-cleft, spiraled. Capsule pendulous to nodding, ovoid, 1.2–
1.5 cm, unequally 3-winged; abaxial wing 1.6–2.2 cm; lateral
wings smaller. 2n = 52*.
● Shaded moist forest floors, trailsides; 700–1600 m. WC Taiwan
(Jiayi, Nantou).
92. Begonia luochengensis S. M. Ku et al., Bot. Bull. Acad. Sin.
45: 357. 2004.
罗 城 秋 海 棠 luo cheng qiu hai tang
Herbs, rhizomatous. Rhizomes creeping, 8–20 mm in diam.
Leaves all basal; stipules triangular-ovate, 7–10 × 7–9 mm;
petiole 8–30 cm, hirsute-villous; blade abaxially reddish, adaxially
with a white band along midvein, pale green near major
veins, dark brownish to purplish red between major veins,
obliquely ovate to ovate, 10–25 × 5–18 cm, papery, both surfaces
densely pilose, basally 7-veined, tertiary veins fine, randomly
reticulate, base cordate, margin denticulate, apex acuminate
to caudate. Inflorescences with 7–14 flowers in a dichasial
cyme; peduncle 8–22 cm; bracts oblong. Staminate flowers:
tepals 4, outer 2 ovate-orbicular, 1.1–1.2 × 1.2–1.3 cm, inner 2
broadly oblanceolate, ca. 12 × 6.5 mm; androecium zygomorphic;
stamens 20–27; filaments nearly free, subequal, apex subemarginate.
Pistillate flowers: tepals 3, outer 2 pinkish, broadly
ovate-orbicular, 1.3–1.4 × 1.5–1.7 cm, inner 1 obovate, apex
rounded; ovary pinkish, glabrous, unequally 3-winged, 1-loculed
with parietal placentation; abaxial wing oblong to nearly
triangular; styles 3, nearly free; stigmas U-shaped or nearly
reniform. Capsule nodding, 11–17 × 6–7 mm. Fl. Aug–Nov, fr.
Sep–Dec. 2n = 30*.