Friday, March 8, 2024

[Botany • 2024] Begonia auritialata & B. ruchengensis (Begoniaceae) • Two New Species from China


Begonia auritialata  D.K.Tian & H.J.Wei,

in Tian, Wei, Huang, Wu, Chen, Guo, Sun, Wang, Gao et Li. 2024.
 
Abstract
China has an exceptional diversity in Begonia, holding the second largest number of described species in this genus at the national level. Many new taxa need to be explored and described. This paper reports two new species, Begonia ruchengensis (B. sect. Reichenheimia) and B. auritalata (B. sect. Platycentrum), from Hunan province and Guizhou province, respectively. Besides the detailed morphology description, color illustrations, and line drawings, the diagnoses of these two species distinguished from their allied taxa are provided. Their conservation statuses are evaluated according to The Guidelines for Using the IUCN Red List Categories.

Keyword: Begonia ruchengensis, Begonia auritalata, new taxa, taxonomy, Flora of China, morphology, conservation

  Morphology of Begonia ruchengensis
A. Mature flowering plant; B. Underground tubers; C. Leaf shape and texture; D, E. Indumentum of adaxial and abaxial leaf surface; F. Branch of inflorescence; G Front view of staminate flowers showing color and size variation; H. Side view of androecium with few stamens; I. Front view of pistillate flower; J, K. Side and adaxial views of fruit; L. Dissected ovary showing thickly unilamellate placentae and unequal wings. (Photos by Daike Tian)

Begonia ruchengensis D.K.Tian, sp. nov.
 (sect. Reichenheimia
汝城秋海棠

Diagnosis: This new species is mostly similar to B. fimbristipula Hance in similar plant size, leaf shape, leaf hairs, and morphology of flowers and fruits, but differs mainly in its thickly unillamelate (vs. thinly bilamellate) placentae of the ovary, later (Jun.–Oct. vs. Apr.–Jun.) flowering time, and smaller flower size (5–11 × 5–10 mm vs. 8–15 × 8–12 mm outer tepals of staminate flower).

Etymology: The epithet “ruchengensis” is derived from Rucheng, a county name of Hunan province, where the type of the new species is collected.


  

Habitat, habit and morphology of Begonia auritialata
A. Habitat near waterfall; B. Habit; C. Densely hairy petiole; D. Flowering plant with short inflorescence; E. Stems growing along rock surface; F. Unevenly green leaf; G. Indumentum on adaxial leaf surface.
(Photos by Daike Tian)

Begonia auritalata D.K.Tian & H.J.Wei, sp. nov. 
(sect. Platycentrum) 
耳翅秋海棠

Diagnosis: The new species is mostly similar to B. villifolia Irmsch. in hairy leaves, flowers and fruits, but is easily differentiated by its 3 (vs. 2) incomplete-locular ovary, concaved (vs. flat) abaxial wing, shorter (to 60 vs. to 100 cm) plant, usually multicolored (vs. pure green) leaf, early (Feb. to Mar. vs. May to Jul.) flowering time. It is also morphologically close to B. khaophanomensis Phutthai & M.Hughes (Phutthai and Hughes, 2016) native to Thailand in the same section, but differs mainly by the latter’s leaf lobed (vs. unlobed), and abaxial wing larger (4 cm vs. ca. 1 cm long), and wing shape (oblong or obliquely triangular vs. auricular).

Etymology: The epithet “auritalata” is derived from its auricular and concave abaxial wing of fruit.  


Daike Tian, Hongjing Wei, Cunzhong Huang, Lei Wu, Zhilin Chen, Zhiyou Guo, Xiaojun Sun, Songwei Wang, Qingmei Gao and Xin Li. 2024. Two New Species of Begoniaceae from China mainland. Taiwania. 69(1); 89 - 98. DOI: 10.6165/tai.2024.69.89