Begonia circularis
Species Information
Classification and Distribution
Begonia circularis is a monoecious, rhizomatous herb endemic to Thach An District, Cao Bang Province, Vietnam. It is located near the border between Vietnam and China and is specifically found in the cracks of mossy rocks on semi-shaded limestone cliffs in evergreen broad-leaved forests at an elevation of approximately 600 meters.
Characteristics
This begonia species features stout creeping rhizomes, deciduous reddish stipules, and red to reddish-green petioles. Its leaves are alternate and asymmetric, widely ovate to widely elliptic, with a circular foliar variegation pattern. The leaves are magenta hispid on the abaxial surface and have a distinctive silvery green to lemon green ring on the adaxial surface.
Flower Details
- Staminate flowers: They have four tepals, with outer tepals being broadly ovate and the inner tepals being oblanceolate and pinkish to white. The androecium is zygomorphic. - Pistillate flowers: These flowers have three tepals, with outer tepals being widely obovate to orbicular and inner tepals being narrowly elliptic. The ovary is reddish, trigonous-ellipsoid, and 3-winged, with unequal wings.
Etymology
The specific epithet "circularis" refers to the circular foliar variegation pattern of the new species.
Similar Species
Begonia circularis somewhat resembles B. lanternaria and B. picturata in the variegated foliage. A comparison of salient features of the three species is shown in Table 2.
Chromosome Cytology
Begonia circularis has a somatic chromosome number of 2n = 30.
