ABSTRACT
Begonia catbensis, a new species in Begonia sect. Coelocentrum is described and illustrated. The new species was discovered in lowland limestone hills at Cat Ba National Park and can be easily distinguished from all its congeners by having dendritic hairs on the petiole, adaxial veins and stipules, fimbriate bracts and bracteoles, dense conical bullae on the upper surface of the leaf blade, two tepals in the pistillate flowers and a glabrescent ovary with verrucose wings. Based on IUCN Criteria, the species is currently assessed as "Endangered" (D).
ABSTRACT
One new species and one new variety of Gesneriaceae in Vietnam are described, viz. Paraboea sinensis var. glabrissimavar. nov. and Primulina xuansonensis sp. nov. These two new taxa grow in limestone regions in North Vietnam. The former new variety differs from Paraboea sinensis (Oliv.) Burtt var. sinensis in its young leaf abaxially, stem and peduncle sparsely and thin pannose, acute top of leaves, pistil glandular-pubescent or pubescent. The latter new species differs in its bracts 1.6-2.5 × 1.3-1.5 cm, corolla 3-3.5 cm long, corolla tube slightly curved near the base and inflated on the adaxial surface near the corolla lobes, and corolla abaxial lip lobes rounded. The two new taxa grow at Xuan Son National Natural Reserve, North Vietnam and remain undisturbed with low risk of extinction.
ABSTRACT
Since 2016, KIB (Kunming Institute of Botany) and CPC (Centre for Plant Conservation of Vietnam) have conducted several surveys in the transboundary karst regions in Northern Vietnam and Southern China and seven new species in the genus Begonia Linn. (Begoniaceae) are firstly described. Amongst them, two species, Begonia albopunctata Y.M. Shui, W.H. Chen & H.Q. Nguyen and B. erectocarpa H.Q. Nguyen, Y.M. Shui & W.H. Chen, respectively belong to section Sphenanthera with berry fruits and section Leprosae with clavate berry fruits; four species, B. gulongshanensis Y.M. Shui & W. H. Chen, B. minissima H.Q. Nguyen, Y.M. Shui & W.H. Chen, B. mollissima Y.M. Shui, H.Q. Nguyen & W.H. Chen, B. rhytidophylla Y.M. Shui & W.H. Chen, belong to section Coelocentrum with parietal placentation; one species, Begonia bambusetorum H.Q. Nguyen, Y.M. Shui & W.H. Chen, belongs to section Diploclinium with 3-loculed ovary and capsules. The diagnostic characters of these species are described and illustrated in the text and photographs.
ABSTRACT
BACKGROUND: Species of Begonia are richly represented in limestone karst areas across the Sino-Vietnamese border. More than one hundred species were known, many of which were documented recently. RESULTS: In continuation of our systematic studies of Asian Begonia, we report six species of Begonia that are unknown to science, namely B. caobangensis [sect. Platycentrum], B. circularis, B. melanobullata, B. langsonensis, B.locii and B. montaniformis [sect. Coelocentrum] from Northern Vietnam. Diagnostic features that separate them from morphologically allied species are provided. Somatic chromosome numbers were determined, which supports their placement in the respective sections. Foliar SEM microphotographs were taken and described. CONCLUSION: A careful study of the literature, herbarium specimens and living plants, both in the wild and in cultivation in the experimental greenhouse, supports the recognition of the six new species, which are described and illustrated.
