Begonia luochengensis

B. luochengensis

Quick Species Info

Species	Begonia luochengensis
Region	Southern China
Country	China
Year published	2004
Date of Origin
Plant Type	Rhizomatous
Section	Coelocentrum
Chr 2n	30

Species Information

Classification and Distribution

Begonia luochengensis is a species of Begonia native to the karst area in southern China. It was first described and published by S. M. Ku, C.-I Peng & Y. Liu in 2004.

Habitat

This species typically grows on semishaded, dry or slightly moist limestone hills.

Characteristics

Begonia luochengensis is a monoecious, perennial, and rhizomatous plant. The rhizome is succulent, creeping, brown, and sparsely hairy near the petiole base or scar, measuring 8-20 mm in diameter, with internodes 8-12 mm long. The stipules are persistent, triangular-ovate, sparsely villous to glabrous on the abaxial surface. They are herbaceous, greenish-hyaline, approximately 7-10 mm long and 7-9 mm wide, with an aristate apex and margin that is ciliate-dentate or long-ciliate.

The leaves are alternate, tomentose on the adaxial surface, with reddish hairs that are erect or slightly ascending and curved at the tips. They are densely hairy along major veins and moderately along veinlets on the abaxial surface. The leaves are simple, asymmetric, obliquely ovate, chartaceous, and exhibit beautiful maculations on the adaxial surface, often along the midrib, forming a white zone (often composed of many little white spots). The upper surface is pale green near the major veins and major lateral veins, dark brownish to purplish red between major veins and major lateral veins, and reddish on the abaxial surface. The leaves measure (10-) 15-20 (-25) cm long (including basal lobes) and (5-) 7-12 (-18) cm wide, with an apex that is acuminate to caudate, a base that is cordate, and a margin that is denticulate or ciliate-dentate. Venation is basally 7-palmate, pinnate along the midrib, with 3-5 major lateral veins on each side. Petioles are brown, terete, 8-20 (-30 when cultivated in a pot) cm long, and 5-7 mm in diameter. They are villous, with whitish hairs that are dense, straight to curly, and somewhat reflexed.

Flower Details

Inflorescences are axillary, arising directly from the rhizome, cymose, and 2-4-branched, with 7-14 flowers. Peduncles are well-developed, brownish, measuring 8-22 cm long and 3-4 mm in diameter, and they are nearly glabrous. Pedicels are reddish, ascending in staminate flowers and horizontal to pendant in carpellate flowers. Bracts are caducous, oblong, herbaceous, green to reddish, measuring 6-9 mm long and 4-5 mm wide, with an apex that is acute to obtuse and margin that is sparsely ciliate-serrate.

Tepals are glabrous, with entire margins. Staminate flowers have 4 tepals, with the outer 2 pinkish on the adaxial surface and reddish on the abaxial surface. They are ovate-orbiculate, with a slightly cordate base and a rounded apex, measuring 11-12 mm long and 12-13 mm wide. The inner 2 tepals are pinkish, broadly oblanceolate, and have an obtuse apex, measuring about 12 mm long and about 6.5 mm wide. The androecium is zygomorphic, with stamens numbering 20-27 and having a golf-club shape. Filaments are free, nearly equal in length at about 1.6 mm long, and anthers are 2-locular, slightly compressed, oblong, and have a slightly emarginate apex, appearing yellowish and measuring about 1.4 mm long.

Carpellate flowers consist of 3 tepals, with the outer 2 pinkish on the adaxial surface and pink on the abaxial surface, broadly ovate-orbiculate, with a rounded apex, measuring 13-14 mm long and 15-17 mm wide. The inner tepal is obovate with a rounded apex. The ovary is glabrous and pinkish at anthesis, with 3 wings of unequal size. The lateral wings are much narrower, measuring 3-4 mm high, while the abaxial wing is oblong to nearly triangular, measuring about 6 mm high and 8-9 mm wide. The locule is 1, with intruded parietal placentation. There are 3 styles that are nearly free (slightly fused at the base), yellow, and measure about 4 mm long, with the summit being U-shaped. The stigmas are U-form or nearly reniform.

Etymology

The specific epithet "luochengensis" refers to the Luocheng minority county where this species was collected.

Comparison to Similar Species

Begonia luochengensis can be distinguished from similar species, such as B. luzhaiensis T. C. Ku, by its ovate leaves that are densely pubescent and have a remarkable white band along the midrib on the upper surfaces. It also differs from B. porteri H. Lév. & Vaniot by its larger size and rhizome characteristics.

References

- Ku, S.-M., Peng, C.-I., & Liu, Y. (2004). Notes on Begonia (sect. Coelocentrum, Begoniaceae) from Guangxi, China, with the report of two new species. Botanical Bulletin of Academia Sinica, 45, 353-364.

Photos

File:Begonia luochengensis.jpg

Begonia luochengensis

External Links

Links to pages related to this species