Begonia garrettii Craib, Bull. Misc. Inform. Kew

Chen, Wen-Hong, Radbouchoom, Sirilak, Nguyen, Hieu Quang, Phutthai, Thamarat, Averyanov, Leonid V. & Shui, Yu-Min, 2018, Reassessment of Begonia arboreta and B. sonlaensis (Begoniaceae) based on field observation and type examination, Phytotaxa 381 (1), pp. 132-140 : 133-136

Begonia garrettii Craib, Bull. Misc. Inform. Kew : 411, 1930. Type:— THAILAND. Chiang Mai: east slope ending in

Doi Pa Mawn, elev. 1450 m, 22 September 1927, flower white with violet red tinge, on rocks, aneroid, H.B.G. Garrett

462 ( holotype: ABD [ ABDUH 2 /620]!; isotype: ABD [ ABDUH: 2/619]!, K [000761183, 000761184, 000761185]!, E

[00265176]!, TCD [0017184]! ( Figs. 2 & 3 ).

— Begonia arboreta Y.M.Shui, Acta Bot. Yunnan. 24(3): 307, fig. 1, 2002. Type:— CHINA. Yunnan, S.K. Wu, Y.M. Shui, Y.P. Yang, L.H. Liu, J.H. He, J. Murata, H. Nagamasu, T. Sugawara, X. Chen, N. Murakami 144 (holotype: KUN [0773200]!). syn. nov.

Distribution and Ecology:—South Yunnan in Southwestern China and Chiang Mai province in the north of Thailand ( Fig. 1 ). It grows exclusively as an epiphyte in montane forests at elevation 1400–1860 m a.s.l.

Examined specimens:— CHINA. Yunnan: Luchun county, Hydrostation , on trees along deep valley, elev. 1650 m, herb 0.4–1.1 m tall, flower white, 28 July 2005, Y. M. Shui et al. 44373 ( KUN!) ; ibid., Luchun county, Huanglianshan National Natural Reserve , 25 August 2013, D. K. Tian & C. Li TDK 1272 ( CSH [0015717]!) . THAILAND. Chiang Mai: en route from Pha Mawn (Ban Yang) to the camp., elev. 900–1800 m, 2 October 1971, G. Murata, K. Iwasuki, C. Pengkiai, C. Charamphol T-15698 ( BKF [59155]!) ; ibid., Doi Pha Hom Pok National Park, trail from Kew Lorn Ranger Substation to Pang Mang Kon , at elev. 1860 m, 20°4’14”N, 99°7’49”E, gully in lower montane forest, granite bedrock, epiphytic herb on tree trunk, 2 October 2009, D. J. Middleton, S. Lindsay & P. Suksathan 5048 ( E [00348476]!) .

Note:—The plants from China and Thailand are morphologically uniform with respect to the epiphytic tuberous habit, five petals of female flowers and narrowly obovate fruits with slightly obtuse apex of the fruit wings ( Figs. 2 & 3 ). In fact, when B. arboreta Shui (2002: 307) was described, the similar species used in the protologue for the diagnosis was B. garrettii Craib (1930: 411) . Hence the diagnostic characters used for B. arboreta (no cauline leaves and obovate wings) ( Fig. 2–H ) fit within the variation seen in B. garrettii and we consider the two to be conspecific.

Begonia pseudodryadis C.Y.Wu, Acta Phytotaxonom. Sin. 33(3): 251, fig. 22, 1995. Type:— CHINA. Yunnan: Pingbian county, Yaoshan , elev. 1320 m, on mossy rocks in valley, 6 July 1953, P.Y. Mao 2389 (holotype: KUN [0371714]!; isotype: KUN [0371713]!, IBSC [19530706]!) ( Figs. 4 & 5 ).

— Begonia sonlaensis Aver. , Turczaninowia 15(2): 26, 2012. Type:— VIETNAM. Son La Province: L. Averyanov, CPC 1876aa (holotype: LE!). syn. nov.

Distribution and Ecology:—The species is distributed in Southeastern Yunnan, Southwestern China, and Sonla and Dien Bien provinces, northwestern Vietnam ( Fig. 1 ). It grows exclusively as a lithophyte on limestone karstic hills, commonly on cliffs or among rocks at elevation 670–1800 m a.s.l.

Examined specimens:— CHINA. Yunnan province: Hekou county, Lianhuatang community, Youmaji village , on limestone hills, elev. 1350 m, 17 November 1997, herb, 15–30 cm tall, tepals 4, pinkish, Y. M. Shui 001065 ( KUN) ; ibid., Xinjie community, Yaomaji village, in the limestone forests, elev. 1400–1600 m, 13 April 2000, Y. M. Shui 12854 (0530407, KUN!). Same province , Maguan county , Gulinqing, 22°44’35”N, 103°59’28”E, opposite Arboratumexamining Station , on limestone hills, herb, 15 cm tall, 16 October 2002, Y. M. Shui, W. H. Chen and J. S. Sheng 31576 ( KUN!) ; ibid., Dawantian , elev. 650 m, in the dense forest on limestone hills, herb, 30 cm tall, flower pink, 18 June 2003, Y. M. Shui et al. 32098 ( KUN!) ; ibid., limestone mountain, elev. 700 m, 28 December 1997, Yan Zhi-Qiang 0098720 ( KUN!) . VIETNAM. Dien Bien Province: Tua Chua district, Trung Thu municipality, Trung Thu village , around point 21°55’38”N, 103°18’05”E., highly degraded primary evergreen broad-leaved forest on very steep slopes and along remnant ridge composed of solid limestone, elev. 1350–1450 m, lithophytic rosulate herb on shady mossy cliffs, flowers pink, anthers yellow, common, 10 April 2011, L. Averyanov, P. K. Loc, N. Q. Hieu, N. T. Vinh CPC 2127 ( CPC!, HN!) ; ibid., Xa Nhe Municipality , around point 21°52’35”N, 103°24’21”E, highly degraded primary evergreen broad-leaved dry forest on very steep slopes and on tops of remnant mountains composed of solid limestone, elev. 850–1050 m, lithophytic herb on shady mossy cliffs, flowers pink-purple, anthers and stigmas yellow, leaves velvety dark green with palmate irregular light green spots, very common, 11 April 2011, L. Averyanov, P. K. Loc, N. Q. Hieu, N. T. Vinh CPC 2199 ( CPC!, HN!) ; ibid., Ta Xi Lang village, around point 21°57’17”N, 103°25’31”E, highly degraded primary and secondary evergreen broad-leaved forest on very steep slopes and on tops of remnant mountains composed with solid limestone, elev. 850–950 m, lithophytic herb on shady cliffs, flowers pink, anthers and stigmas yellow, leaves dark velvety green-gray, often with palmate whitish spots, locally very common, 13 April 2011, L. Averyanov, P. K. Loc, N. Q. Hieu, N. T. Vinh CPC 2292 ( CPC!, HN!). Son La province: Yen Chau district, Muong Lum community, Na Lang village Dan Kho Mountain , 21°01’16.4”N, 104°30’54”E, elev. 942 m, 9 December 2017, Y. M. Shui, W. H. Chen, S. W. Guo, N. Q. Hieu, N. T. Hiep, N. S. Khang, L. V. Chung, H. V. Tinh, H. M. Hop, H. V. Vu, H. V. Dong CK 1801 ( CPC!, KUN!) ; ibid., Na Hat village, May Mo valley , 21°00’35”N, 104°29’06”E, elev. 1140 m, 10 December 2017, Y. M. Shui, W. H. Chen, S. W. Guo, N. Q. Hieu, N. T. Hiep, N. S. Khang, L. V. Chung, H. V. Tinh, H. M. Hop, H. V. Vu, H. V. Dong CK 1830, CK1831, CK1832 ( CPC!, KUN!) .

Notes:—The studied plants from China and Vietnam are morphologically consistent and restricted to limestone habitat. They share a glabrous habit, an acute tepal apex and parietal placentation at the middle position of the ovary ( Figs. 4 & 5 ) ( Wu & Ku 1995, Averyanov & Nguyen 2012, Chung et al. 2014). During the 2016–2017 survey in Vietnam ( Chen et al. 2018), we finally confirmed the conspecific characters of two species especially after collecting the variegated individuals ( Fig. 4F ).

Figures

FIGURE 1. The distribution of Begonia arboreta Y.M.Shui (z), Begonia garrettii Craib (Δ), Begonia pseudodryadis C.Y.Wu (•) and Begonia sonlaensis Aver. (¢).

FIGURE 2. Living plants of Begonia garrettii Craib (A–B) and Begonia arboreta Y.M.Shui (C–H) A. Plant, adaxial leaf and fruit; B. Plant, abaxial leaf and fruit; C. & D. Habitats; E. Plant, abaxial leaf and inflorescence; F. Male flower and close up of anther; G. Inflorescence; H. Fruit, side and front views (A & B photographs by D. J. Middleton, C–H photographs by Yu-Min Shui)

FIGURE 3. Specimens of Begonia garrettii Craib (A, C, D, E, G) and Begonia arboreta Y.M.Shui (B, F) A. Type of B. garrettii; B. Holotype of B. arboreta; C. Close-up leaf; D. Close-up of male flowers; E. Close-up of female flowers; F. Close-up of fruits; G. Closeup of fruit with obtuse apex of the wings. (Specimens no.: A & E, K [000761183]!; B & F, KUN [0773200]!; C, K [000761184]!; D, K [000761184]!; G, K [000761185]!).

FIGURE 4. Begonia pseudodryadis C.Y.Wu (A–E) & Begonia sonlaensis Aver. (F–I) A. Habitat; B. Adaxial leaf surface; C. Abaxial leaf surface; D. Male flower and close-up of anthers; E. Fruit; F. Habitat; G. Adaxial leaf surface; H. Abaxial leaf surface; I. Dried fruit. (A–E, photographs by Yu-Min Shui, F–I, by Shi-Wei Guo)

FIGURE 5. The materials of the type specimens of Begonia pseudodryadis C.Y.Wu (A–C) and Begonia sonlaensis Aver. (D–G) A. Holotype; B. Specimen from type locality; C. & F. Rhizome and stipule; G. Dry Capsule. (Specimen no.: A, B & C from P-I Mao 2389 (KUN [0371714]!); D from the holotype of B. sonlaensis; E, F & G from Y. M. Shui et al. CK 1801 (KUN!)).