BS 55 219 Distribution patterns and diversity centres of in SE Asia

Kai Larsen

Larsen, K. 2005. Distribution patterns and diversity centres of Zingiberaceae in SE Asia. Biol. Skr. 55: 219-228. ISSN 0366-3612. ISBN 87-7304-304-4.

A revised classification, based on molecular and morphological data, has recently been proposed. The new classification divides the family into four subfamilies. 1: The Tamijioideae including the recently discovered monotypic Tamijia from N Borneo. 2: The Siphonochiloideae includ­ ing the genus Siphonochilus (15) restricted to tropical Africa. The remaining c. 50 genera, with c. 1300 species are classified in two subfamilies: 3: The Alpinioideae, the most widespread, is repre­ sented by Renealmia (100) in the Neotropics and Africa, Aframomum (50) and Aulotandra (5) in Africa while the remaining c. 20 genera with some 700 species are all from the Asian tropics. 4: The , a far more diverse group with c. 30 genera comprising c. 600 species. They are only represented in Asia. The main centre of distribution for the two large subfamilies is SE Asia. The biogeography of all genera from this region is presented and it is shown that the Alpin­ ioideae have their main centre of diversity in the Malesian region while the Zingiberoideae are centred in the northern monsoon region with Indochina having the highest diversity. In the light of the many recent discoveries of new genera and species it is also stressed that, besides continued studies on the molecular based phylogeny, basic field-work is still highly needed.

Kai Larsen, Department of Systematic Botany, Aarhus University. Building 540, Ny Munkegade 116, DK- 8000 Aarhus C. Denmark. E-mail: [email protected]

Introduction - Subfamily Siphonochiloideae. Schuman treated the genus Siphonochilus (15), re­ In 1904 Schumann published his monograph stricted to tropical Africa, as . on the Zingiberaceae. The system presented Surprisingly, molecular studies have re­ here was, with some refinements, mainly by vealed it as a very distinct and basic group. Loesener (1930), Holttum (1950), and Burtt - Subfamily Alpinioideae (Fig. 2A,B). About and Smith (1972), accepted throughout a cen­ 20 genera with c. 700 species are the most tury. A revised classification, based on molecu­ widespread, represented by Renealmia lar and morphological data, was proposed by (100) in the neotropics and Africa, Kress et al. (2002) (Fig. 1). Aframomum (50) and Aulotandra (5) in The new classification divides the family into Africa while the remaining genera are all four subfamilies. restricted to Asia. - Subfamily Tamijioideae. This subfamily - Subfamily Zingiberoideae (Fig. 2C-F). The comprises only one genus, the recently most diverse group with c. 30 genera com­ discovered, monotypic Tamijia restricted prising c. 600 species, are only repre­ to N Borneo (Sakai & Nagamasu 2000). sented in Asia. 220 BS 55

The author has studied the family in SE Asia robust rhizome and a terminal inflorescence. for over 30 years and is organizer of and con­ Several attemps have been made to split the tributor to the treatment of the family for the genus into smaller genera, the latest by Holt- Flora of and the Flora Malesiana. Sev­ turn (1950), but none of these have been satis­ eral years ago, I established a team of a dozen factory. Smith (1990) joined the segregate gen­ botanists, Thai and foreign, to treat the family era and gave a framework for an infrageneric in Thailand. Among these are six Ph D stu­ classification. The molecular analysis, however, dents from Thailand who have now for 2-4 has shown that Alpinia is polyphyletic consist­ years collected throughout the country. This ing of at least four groups not really corre­ has increased our knowledge of the diversity of sponding with those of Smith. There is no the family in this large country immensely. In recent revision of the genus, but the overall dis­ the last published checklist of Thai - tributional pattern is representative for the aceae (Larsen 1996), 200 species were subfamily. The largest number of species included; today close to 300 species have been occurs in Malesia with about 60 species in documented. Three new genera have been dis­ (Wu & Larsen 2000) and the Indochi­ covered and described as well as numerous nese region. Thus clearly two diversity centres new species, and we are aware of several unde­ exist: one in central Malesia and one in the scribed taxa. northern monsoon region where the species are mostly found in montane evergreen forests. Several undescribed species are Subfamily Alpinioideae expected. The Alpinioideae consists of c. 20 genera after Amomum - The situation in Amomum, with Nanochilus, Rhynchanthus and Pommereschea, some 150 species, is similar to some extent to three small genera from the northern mon­ Alpinia. This genus also seems to be poly­ soon area, have been transferred to the Zin- phyletic even if only few species have been sam­ giberoideae based on molecular studies. This pled in the analysis. Again no recent revision makes the subfamily more uniform morpho­ exists, and much field-work is needed as many logically, consisting of large herbs with a main new species have been described in recent distribution in the lowland forests of the Male- years mainly from northern Borneo. It is sian region. The distichy of the leaves are trans­ remarkable that there are far fewer collections verse to the rhizome and the lateral staminodes of Amomum than of Alpinia in the large are reduced to small teeth at the base of the herbaria. This may be due to the less eye-catch­ labellum. To illustrate the distribution patterns ing, basal inflorescences and shorter flowering in the Alpinioideae, the genera are presented period. There are two diversity centres: one, here in groups corresponding to the results of with the majority of species, in Borneo and one the molecular analysis in which two tribes, the in China-Indochina with about one third of the Alpinieae and the Riedelieae, are recognized. species. The first one is by far the largest. Etlingera - This, the third largest genus with about 80 species of large forest herbs was, in its present circumscription, established by Burtt & Tribe Alpinieae Smith (1986) who joined Achasma, Geanthus Alpinia - This is the largest genus in the Zin- and Nicolaia. This genus may also be poly­ giberaceae with over 200 species (Fig. 2A). The phyletic. Again we find the same overall pat­ are tall herbs up to 8 (-12) m with a tern with a distribution from the southern BS 55 221

Alpinioideae

Zingiberoideae

Tamijioideae Siphonochiloideae Fig. 1. Cladogram showing the system of the Zingiberaceae as proposed by Kress et al. (2002). Reproduced with permission from Amer. J. Bot. 89. 2002. 222 BS 55

Fig. 2. Representative species of SE Asian Zingiberaceae. The species represent the two subfamilies Alpinioideae (A-B) and Zingiberoideae (C-F) and the tribes Alpinieae (A: Alpinia malaccensis), Riedelieae (B: Burbidgea nitidd), Globbeae (C: Gag- nepainia godefroyï) and Zingibereae (D: Zingiber puberulum, E: sp. nov., F: Laosanthus graminifolius).

Himalayas throughout SE Asia to N Queens­ pattern as described for the preceeding genera land with the main diversity centre in Malesia, with c. 50 species in Malesia and NE Australia. particularly Borneo. There are only few species There are a few Malaysian species, some of in Indochina and two species in China, one which also occur in S Thailand. Further north, endemic, E. yunnanensis, and one, E. littoralis, a one species is endemic to N Vietnam, and two very widespread species. Also in this genus to China (Hainan and Tibet). much field-work is needed. Plagiostachys - About 25 species of this taxo­ Hornstedtia - This genus follows the same nomically poorly studied genus are mainly BS 55 223 found in the Malcsian region. One species has Philippines. The place of the monotypic genus recently been collected in S. Thailand, one Paramomum, endemic to China, treated by undescribed species is found in central Thai­ Larsen et al. (1998) as Amomum, was found by land while one, P austrosinensis, is endemic to S Kress et al. (2002) to be close to Elettariopsis, a China. A problem with the genus is that in genus with uncertain circumscription. most species the inflorescence dissolves after anthesis in a muscilagenous substance, causing most old herbarium material to be of little use. Tribe Riedelieae Kress et al. (2002) included only two species in The tribe Riedelieae consists of 4 or 5 genera their molecular analysis. The genus follow the with long capsules opening longitudinally and same pattern of distribution as the genera extraderai nectaries on the leaves. above with the majority of the species in Male- Burbidgea, Riedelia, Pleuranthodium and Sia­ sia and a narrow “tail” of endemic species in manthus - Burbidgea (8; Fig. 2B) is endemic to the continental monsoon region. Borneo whereas Riedelia (60) and Pleuran­ Geostachys - This genus was not included in thodium (25) are both distributed in Estern the molecular analysis by Kress et al. (2002). It Malesia to N. Australia. Finally Siamanthus (1) seems to be related to Amomum but is recogniz­ as described by Larsen and Mood (1998), is able by the leaves in a radical tuft on the rhi­ one of the strangest endemisms from S Thai­ zome raised above the ground by stilt-roots and land possessing a bilabiate floral structure a basal inflorescence with sterile bracts at base quite different from what is known elsewhere and tubular bracteoles enclosing the cincinni. in the Zingiberaceae.The tribe Riedelieae Holttum (1950) was the first to study Geostachys again appears to have the same distribution from Peninsular Malaysia, where he found that pattern as the Alpinioideae, but here it is even it had its centre of diversity in contrast to the more pronounced, with some 100 species dis­ other genera in the Alpinioideae. It is also tributed throughout the East Malesian area characteristic that all species are found as and only one, Siamanthus, in Thailand. endemics occurring in montane forests at alti­ Siliquamomum - Finally, Siliquamomum is a tudes above 800 m. I have for several years stud­ monotypic genus from N Vietnam and adja­ ied the genus and described new species from cent S China. It seems difficult to place at pre­ Thailand, all mountain endemics (Larsen sent and Kress et al. (2002) included it as incerta 1962, 2001). Schumann (1904) enumerated 5 sedis. It may be related to Siamanthus even if the species, Holttum (1950) recognized 14 species, floral morphology is very different. today at least 24 species are known, including 10 endemic to Thailand, Cambodia, Vietnam, Sumatra, Borneo. Subfamily Zingiberoideae Small genera - Besides the larger genera The Zingiberoideae consists of c 30 genera. treated above, some smaller genera with one or Only Zingiber matches in size the largest genera few species belong to this tribe. Not all of these in the Alpinioideae. The species are generally have been available for the molecular analysis. smaller herbs mostly with a pronounced sea­ These taxa include Cyphostigma (1), in Sri sonal dormancy period adapted to the mon­ Lanka, Elettaria (7), in Malesia, Elettariopsis soon climate. In many genera we find species (10), in Malesia, Geocharis (7), in eastern Male­ that produce inflorescences at the end of the sia, Leptosolena (1), in the Philippines, and dry season and leafy shoots in the rainy season. Vanoverbergla (2), from China (Taiwan) to the The distichy of the leaves are parallel to the rhi- 224 BS 55

zome. The lateral staminodes are well devel­ Kaempferia — The genus Kaempferia consists oped, either free from the labellum or of small herbs with a pronounced dormancy attached to it as in Zingiber. The Zin- period. Intensive collecting activities in Thai­ giberoideae includes the three tribes Zin- land and neighbouring countries have gibereae, Hedychieae, and Globbeae in Schu­ revealed an extraordinary diversity in lime­ mann’s (1904) classification. Kress et al. (2002) stone regions. At present about 10 new species recognize two tribes, the Zingibereae and the from Thailand and Laos are being prepared Globbeae. Finally the genus , for publication (Jenjittikul, pers. comm.). This established by Larsen (1964), is placed as genus is widespread in tropical Asia, but with incerta sedis. The largest tribe is the Zingibereae most of the species in the Indochinese region. with some 25 genera. Kaempferia is a well-defined genus according to Kress et al. (2002), still I suggest that K. scaposa from India should be excluded due to its devi­ Tribe Zingibereae ating morphology. The small genus Haplo­ Zingiber -The Zingiber-ciade comprises Zingiber, chorema, endemic to Borneo, is very similar to Kaempferia, , , Disti­ Kaempferia. It has not been included in the mol­ chochlamys, , Haplochorema and Cor- ecular studies. nukaempferia. Zingiber deviates in many ways Scaphochlamys-The genus Scaphochlamys was from the other genera. It is a large genus with studied in depth by Holttum (1950) in connec­ between 100-150 species (Fig. 2D), widespread tion with his treatment of the Peninsular from subtropical Japan through Malesia to Malaysian Zingiberaceae. It is a group of small Indochina, China, and India. Most species are herbs with tufted leaves, spirally arranged evergreen, medium-sized herbs belonging to bracts, glandular floral parts and patent sta­ the lowland forests. The flowers are character­ minodes; nearly all species are restricted to the istic in possessing a long produced connective. lowland forest of the Malay Peninsula. The uncertain number of species is due to our Haniffia - The genus Haniffia was described lack of knowledge of the diversity in the main by Holttum (1950) and is morphologically centres, Borneo and Indochina. This situation close to Scaphochlamys in its floral characters is best illustrated by Thailand. A few years ago with e.g. the glandular hairs and patent stamin­ Larsen (1996) estimated the number of species odes; vegetatively, however, it looks like a small native to Thailand to 25. Then Theilade Zingiber on account of the elongated pseu­ (1999) subsequently described 8 new species dostem. Besides the type species, H. cyanescens, and 2 new records. Most recently, collecting all a second species was recently described in S over the country has increased the number of Thailand, H. albiflora (Larsen & Mood 2000). species to about 50, with 5 new species and sev­ The genus is restricted to the lowland ever­ eral new records (Triboun in prep.). We are green forests of the Malay Peninsula. also aware of several new species from Viet­ - Newman (1995) described nam. A similar situation could be reported the genus Distichochlamys from a limestone from other parts of SE Asia (see also Theilade region in central Vietnam. In floral characters & Mood 1997 and Mood & Theilade 2002). In it matches Scaphochlamys and Haniffia, but the spite of these drastic changes it is clear that bracts are distichous. Geographically, as well as there are two diversity centres: an eastern cen­ ecologically, it is distinctly separated from tre in Borneo and a western one in the Scaphochlamys. A second species was described Indochinese region. by Larsen and Newman (2002), and a third BS 55 225

species by Rhese and Kress (2003). All three species, C. longipetiolata, was collected close to species are from the same limestone region in the border of Laos (Mood & Larsen 1999). central Vietnam. Curcuma - The Cure« wzz-c lade consists of the Boesenbergia - This is a genus that I have large genus Curcuma (Fig. 2E) centred in mon­ studied for several years. The molecular analy­ soon Asia and with a tail of small closely related sis suggests that it is polyphyletic. The genus, as genera in the northern part of the region. Cur­ generally recognized today, is widely distrib­ cuma is, as several of the other genera in the uted, but with two very distinct centres: N Bor­ Zingiberoideae, subject to intense collecting neo and monsoon Asia. Almost every expedi­ through the major part of its distribution area, tion to Brunei, Sarawak and Sabah has brought and important new knowledge of the diversity back undescribed species of Boesenbergia and is accumulating. Almost all species have a dis­ we strongly suspect that there are still more to tinct dormancy period and several develop the be discovered. Also from Thailand, inflorescence before the leafy shoot. From and adjacent regions of India intensive collect­ Thailand new species have recently been ing activities in recent years have revealed sev­ described by Mood and Larsen (2001). In eral new species. Morphologically 3 or 4 rather Larsen et al. (1998) the number of species in distinct groups can be identified: 1. The group the genus was estimated to 50. With our pre­ including the generic type, B. pulcherrima, with sent knowledge it will probably be closer to 80. apical flowering. 2. the Curcumorpha group, and - Two small gen­ based on B. longiflora, which flowers from the era, Hitchenia (3) distributed from western base. 3. An intermediate group (c.g., B. tenuispi- India to Myanmar and Stahlianthus (4) from cata), which has not been studied in the molec­ Myanmar to Thailand are closely related to ular analysis. In all three groups the bracts are Curcuma. distichous, not spirally arranged as described - The genus Smithatris has a simi­ by Rao and Verma (1971) for Curcumorpha (see lar exciting history as . A Larsen 1997). 4. Finally the very polymorphic was in 1998 presented at a horticultural exhibi­ species B. curtisii, with a morphologically dis­ tion in Singapore and here observed by Kress. tinct floral structure may not belong here. It At the same time I had seen other collections has not yet been included in the molecular in Thailand. The Maranthaceae-like leaves and analysis. Thus, there is still a long way to go small flowers with a long corolla tube, which before the phylogeny of the genus (or generic recoils after anthesis, are very characteristic. complex) has been elucidated and under­ Kress and Larsen (2001) described the mater­ stood. ial as a species et genus nova with the species .S'. Cornukaempferia - This, the last genus in the supraneanae. Even if it was new to science, the Zmgifør-clade, has an interesting history. The species has been known by the local people just genus has been known for more than two outside Bangkok for years and used to embell­ decades and sold through American nurseries ish the temples during the Buddhist lent. under various fancy names until Mood and Recently Kress and Htun (2002) described a Larsen (1997) described it. The characteristic second species from Myanmar. flower has a superficial resemblance with Zin­ Laosanthus - This genus was described by giber while the vegetative parts are similar to Larsen and Jenjittikul (2001) as a monotypic Kaempferia. It was described as a monotypic genus from Laos, has a strongly reduced ver­ genus from central northern Thailand with the sion of the Curcuma flower, without lateral sta­ species C. aurantiflora. Soon, however, a second minodes and anther appendages combined 226 BS 55 with free inflorescence bracts and long, narrow author have revealed four new species (unpub­ grass-like leaves (Fig. 2F). It has not yet been lished). included in the molecular analysis. Caulokaempferia - The genus Caulokaempferia , , Pommereschea and Rhyn- may or may not belong in the Zingibereae. canthus - One group, consisting of the genera Kress et al. (2002) keeps it as incerta sedis. This Roscoea (20), Cautleya (2), Pommereschea (2) and genus deserves attention. Larsen (1964) sepa­ Rhyncanthus (6), belongs to the Himalayan ele­ rated it from Kaempferiawhexe it clearly did not ment in the SE Asian floras and have the most belong. At that time seven species were known northwestern distribution of the Asian Zingib- ranging from N India, , N Vietnam to eraceae. The two latter genera formerly were Thailand, i.e. the Himalayan element in conti­ treated as members of the Alpinioideae but fol­ nental SE Asia. All the species are from high lowing the molecular analysis were transferred altitudes, with yellow flowers, unilocular cap­ to the Zingiberoideae. It should be mentioned sule opening by one large window and minute, also that earlier authors (e.g., Burtt & Smith exarillate seeds. In 1972, Larsen and Smith 1972) had suggested that they might be better described, C. alba with white flowers and a placed here. trilocular, fleshy capsule dehiscing by three Pyrgophyllum and Camptandra - The genus valves releasing a few, large seeds with a well Pyrgophyllum is a monotypic genus endemic to developed aril. Some related species with violet S China. Schumann (1904) treated it as part of flowers were later described from other Camptandra. Gagnepain (1908) referred it to plateau mountains (Larsen 2003). The type of Kaempferia (where it clearly does not belong). the genus has yellow flowers and unilocular Larsen and Smith (1972) included it in capsule and may be related to . The Caulokaempferia. Schumann’s placement comes group with white-violet flowers has not yet been closest to the results of the molecular analysis. included in molecular studies, but I strongly Camptandra (3) shares the one large spatha- suspect that it is not related to Caulokaempferia ceous bract with Pyrgophyllum. Biogeographi­ and should be treated as a separate genus, cally Camptandra belongs to the lowland Male- Larsen (2003). The author is working on a sian element found in the evergreen forests in monograph on this group. the Malay Peninsula and Borneo. Nanochilus, Paracautleya, Parakaempferia and - This is a very natural mono­ Stadiochilus - Four monotypic genera of very phyletic genus. It possesses a number of restricted occurrence are poorly known and unique characters, the dense inflorescesences have not been treated in the phylogenetic with imbricate bracts, the long exerted stamen, analysis: Nanochilus (1) from Sumatra, Para­ the development of several flowers at the same cautleya (1) India, Kanara, Parakaempferia (1) time, and the seeds embedded in the more or India, Assam and Stadiochilus (1) Myanmar. less merged arils. The main distribution centre for the c 80 species is clearly monsoon Asia to S China and the Himalayan region; a few species Tribe Globbeae do occur in the Malesian region, particular in Globba, Mantisia, and - Borneo. About half of the species occur in the All previous systematists have recognized this Indochinese region (Sirirugsa & Larsen 1995). tribe as a distinct group consisting of 4 genera, A recently finished monograph is anticipated Globba (90), Mantisia (2), Gagnepainia (3; Fig. (T. Wood in prep.). Ongoing studies on the 2C) and Hemiorchis (3), of which at least the genus in Thailand by P. Sirirugsa and the first three are closely related. The largest genus BS 55 227

Globba has its diversity centre in the Indochi­ The other large subfamily, the Zin- nese monsoon region, but with offshoots to the giberoideae, is far more complex. There are Malay Peninsula, Sumatra and Borneo. M. some well-defined clades with one large genus, Newman is now revising the genus for Thai­ for example Curcuma and a tail of smaller, land, and a monograph by K. Williams is in the closely related genera found in special environ­ pipeline. Mantisia belongs to the Himalayan ments such as isolated limestone areas, sand­ element and may be included in Globba. Gagne- stone table mountains and evergreen forests of painia (3) is restricted to Thailand and adja­ the Malay Peninsula. The overall picture is that cent regions of Laos and Cambodia. From the of a subfamily centred in continental SE Asia molecular analysis is appears, surprisingly, and particularly in the northern monsoon closer to Hemiorchis (3), distributed from India region. Two of the largest genera, Zingiber and to western Thailand. I have always found that Boesenbergia, however, have a distribution pat­ this genus was not belonging naturally to the tern like the majority of the Alpinioideae, with Globbeae. two main centres, one in continental monsoon Asia, the other on Borneo. Some areas of SE Asia are rather well col­ Conclusion lected, e.g. Peninsular Malaysia, Thailand and The intense study of the Zingiberaceae during N Borneo. With so many new taxa of Zingiber­ the last decade has not been equalled since the aceae found in the last few years in Thailand days of Gagnepain (1908), Ridley (1899) and and Sabah, due to intense collecting activities, Schumann (1904) published their valuable there is no doubt that the far less well-known contribution to the knowledge of the family a regions, such as Myanmar, Vietnam, and partic­ century ago. We are now exploring the last ularly Laos and Kalimantan, will in the future, undercollected regions of SE Asia and have bring many new discoveries. found a hitherto unknown richness of diversity In the coming years, molecular studies, and gained a much more precise picture of the clearly, should have high priority as certain diversity centres. Through the very recent mol­ genera cannot yet be placed at present, and ecular studies, we have got a new phylogenetic many have been found to be polyphyletic. As system. This will undoubtedly be adjusted and yet we cannot with any certainty answer the refined in the future as more taxa are question: “How many species of Zingiberaceae included. are there?” Therefore we must also support The overall picture of the two large subfami­ basic field-work in the last remaining wilder­ lies is, however, clear. The Alpinioideae is wide­ ness in SE Asia. spread throughout the tropics but, as for the family, is mainly found in the Asian tropics. It is most diverse in the Malesian region and here Literature cited again Borneo is clearly the main centre on the Burtt, B.L. & Smith, R.M. 1972. Key species in the taxo­ Sunda shelf, while a second less explored cen­ nomic history of Zingiberaceae. Notes Roy. Bot. Gard. tre is placed further East. A third centre, with Edinburgh 31: 177-227. about one third of the species, is in continental Burtt, B.L. & Smith, R.M. 1986. Etlingera: the inclusive monsoon Asia. Some of the genera seem to be name for Achasma, Geanthus and Nicolaia. Notes Roy. Bot. Gard. Edinburgh 43: 235-241. so closely related morphologically that some Gagnepain, F. 1908. Zingiberaceae. In: Gagnepain, F. species may change their position in the future (ed.), Flore Générale de l’Indochine. Vol. 6. Masson et Cie, or genera may be combined. Paris. Pp. 25-121. 228 BS 55

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