Friday, April 29, 2016

[Botany • 2016] A Revision of Rhapis (Arecaceae)

Rhapis kebangensis Henderson sp. nov.
Phong Nga-Ke Bang National Park, Quang Binh, VIETNAM

A revision of the Asian palm genus Rhapis is given based on study of 167 herbarium specimens of wild origin from A, AAU, BH, BK, BKF, GH, HN, HNU, HPNP, IBSC, K, KUN, L, MO, NY, P, SYS, US and application of the Phylogenetic Species Concept to a database comprising 13 qualitative and 16 quantitative variables. Eleven species are recognized, including two new ones. Two species are divided into subspecies.

Keywords: dioecy, Palmae, Vietnam, China

Rhapis is the name given to small, clustering, fan-leaved, dioecious palms that can form large colonies by rhizomes in the understory of tropical and subtropical Asian forests, often on limestone soils. The species are distributed from southern China through Vietnam, Laos, Thailand, and Cambodia, with an outlying population in western Sumatra. The first revision of the genus was that of Beccari (1931), where five species were recognized. Bailey (1939) recognized nine species, and in the most recent revision, Hastings (2003) recognized eight species. 


Rhapis Linnaeus f. in Aiton (1789)

1. Rhapis evansii Henderson sp. nov.
Type:— LAOS. Vientiane: Vangvieng district, Ban Nathong, Tham Poukham, 250–350 m,
1 August 1999, T. Evans 56 (holotype K!, barcode K000462531). (Fig. 1)

2. Rhapis excelsa (Thunberg) Henry in Rehder (1930: 153).
Chamaerops excelsa Thunberg (1784: 130).
Trachycarpus excelsus (Thunberg) Wendland in Gay (1861: 429).
Lectotype (designated by Hastings 2003):— JAPAN. No locality, no date, C. Thunberg sheet number 24386 (lectotype UPS n.v., UPS image!)

3. Rhapis gracilis Burret (1930: 883).
Lectotype (here designated):— CHINA. Prov. Kwangtung: Win Foo, 180 m, 3 October 1928, S. Sin 5338 (lectotype IBSC!) (the holotype at B was destroyed)

4. Rhapis humilis Blume (1836: 54).
Lectotype (designated here):— JAPAN. No locality, no date, C. Thunberg sheet number 24385 (lectotype UPS n.v., UPS image!)

5. Rhapis kebangensis Henderson sp. nov.
Type:—VIETNAM. Quang Binh: Ba Trach district, Phong Nga-Ke Bang National Park.
20 October 2015, A. Henderson & Nguyen Quoc Dung 4048 (holotype FIPI!, isotype NY!). (Fig. 3)

6. Rhapis laosensis Beccari (1910: 225).
Lectotype (designated by Hastings 2003):—LAOS. Saraburi, no date, C. Thorel 3154 (lectotype P!, isolectotype FI!)

6a. Rhapis laosensis subsp. laosensis 
6b. Rhapis laosensis subsp. macrantha (Gagnepain) Henderson comb. & stat. nov.
 Basionym: Rhapis macrantha Gagnepain (1937: 160). 
Type:—VIETNAM. Nord-Annam, Province de Nghe-An (Vinh), Réserve forestière de Co Ba (Ke-Nhe), 15 May 1914, F. Fleury 32535 (holotype P!)

7. Rhapis micrantha Beccari (1910: 220). 
Lectotype (designated by Hastings 2003):—VIETNAM. Dong Ban mountains, Kien Khe 19 April 1884, H.-F. Bon 2345 (lectotype P!, isolectotype FI!)

8. Rhapis puhuongensis Trudgen, Tran Thi Phuong Anh & Henderson (2008: 182). 
Type:—VIETNAM. Nghe An: Quy Hop district, Pu Huong Nature Reserve, behind Reserve office, 300 m, 19°20’N, 105°10’E, 18 March 2007, X. P. Vu, V. D. Nguyen, H. Q. Bui, C. T. Nguyen R. de Kok, T. Utteridge, A. Moore, M. Briggs, M. Trudgen, V. C. Nguyen & D. D. Tran HNK 1748 (holotype HN n.v., isotypes AAU!, K!, NY!, P!)

9. Rhapis robusta Burret (1937: 587).
Lectotype (here designated):— CHINA. Kwangsi: Lungchow, 7 July 1935, S. Ko 55429 (lectotype IBSC!)(the holotype at B was destroyed)

10. Rhapis subtilis Beccari (1910: 227). 
Type:— LAOS. Lakon, 1866–1868, C. Thorel 3099 (holotype P!, isotype FI!)
10a. Rhapis subtilis subsp. subtilis 
10b. Rhapis subtilis subsp. siamensis Henderson comb. & stat. nov. 
Basionym: Rhapis siamensis Hodel (1997: 19). 
Type:—THAILAND. Phatthalung: 13 km N of Phatthalung and 5 km E of main road along side road to coast, 25 April 1997, D. Hodel & P. Vatcharakorn 1652 (holotype BK n.v., isotypes BH!, MO!)

 11. Rhapis vidalii Averyanov, Nguyen Tien Hiep & Phan Ke Loc (2006: 12). 
Type:—VIETNAM. Hoa Binh: Mai Chau district, Van Mai municipality, highway 7, 15 km post, between 20°35’N, 105°02’E and 20°34’N, 105°02’E, 300–350 m, 12 December 2002, D. Harder, N. T. Hiep, L. Averyanov, DKH 8123 (holotype HN n.v., isotype LE n.v.)

Andrew HENDERSON. 2016. A Revision of Rhapis (Arecaceae). Phytotaxa. 258(2): 137–152. DOI: 10.11646/phytotaxa.258.2.3