|Revision of the genus Gmelina L. (Lamiaceae) in Southeast Asia
M. H. Rashid1, J. Parnell and A. Paton2
Department of Botany, Trinity College Dublin, University of Dublin, Ireland
The genus Gmelina is revised for Southeast Asia. 31 taxa consisting of 26 species, 1 subspecies, and 4 varieties are recognised. With a very few exceptions (five species) all are endemic to this region. Seven species, 1 subspecies, and 3 varieties have been reported as new to science: viz. G. chindwinse M. H. Rashid & J. Parnell, G. havilandii M. H. Rashid & A. J. Paton, G. obovata M. H. Rashid, G. obovata var. glabrata M. H. Rashid, G. obovata var. kutaiensis M. H. Rashid, G. parnellii M. H. Rashid, G. palawensis var. matanoeca M. H. Rashid, G. rotundifolia M. H. Rashid & J. Parnell, G. tubularis M. H. Rashid, G. tubularis subsp. pilosa M. H. Rashid & A. J. Paton, and G. yangonensis M. H. Rashid. Two taxa are elevated to varietal and specific level respectively, G. philippensis f. transitoria Moldenke to G. elliptica var. transitoria (Moldenke) M. H. Rashid, and G. uniflora var. villosa Bakh. to Gmelina borneoense M. H. Rashid. G. balansae Dop is reduced to synonymy under G. racemosa (Lour.) Merr. Two species, G. lepidota and G. tonkinensis are newly recorded for Indonesia. Indonesia shows the greatest centre of Gmelina diversity containing 11 species, 1 subspecies, and 3 varieties, almost all of which are endemic to this region. Thailand has the second largest diversity with 4 endemic species, viz. G. attenuata Fletcher, G. paniculata Fletcher, G. parnellii M. H. Rashid, and G. tomentosa Fletcher.
A new infrageneric classification is proposed based on calyx characters. The genus is divided in two sections: section Asiaticum M. H. Rashid & J. Parnell and section Annameticum M. H. Rashid & J. Parnell. Species belong to the section Asiaticum have truncate or subtruncate or with obsolete 4 or 5-sinuate dentate calyx. In contrast, section Annameticum consists the species with bilabiate and conspicuously 5-lobes calyx. All Thai species belong to the section Asiaticum
KEY WORDS: Gmelina, Lamiaceae, Southeast Asia, New species, and Infrageneric classification
1At Present: Department of Botany, University of Chittagong, Chittagong 4331, Bangladesh. e-mail: email@example.com; firstname.lastname@example.org
2Herbarium, Royal Botanic Gardens Kew, Richmond, Surrey TW9 3AE, UK