Two new species of Kaempferia L. (Zingiberaceae) from Cambodia and Lao PDR

Two new species of Kaempferia L. (Zingiberaceae), Kaempferia nemoralis Insis. sp. nov. and Kaempferia pascuorum Insis. sp. nov., from Cambodia and Lao PDR are described and illustrated. Morphological similarities to their closely related taxa are discussed. Kaempferia nemoralis Insis. sp. nov. is compared with Kaempferia larsenii Sirirugsa in its vegetative parts, but distinguished by the following characters: whole plant taller, leaf sheath and young shoot apex green, petiole absent. It differs from Kaempferia rotunda L. in its floral parts by the following characters: presence of peduncle, floral tube longer, labellum purple with white line at centre, anther crest obovate, bifid, apex irregularly rounded and ovary glabrous. Kaempferia pascuorum Insis. sp. nov. is compared with Kaempferia larsenii Sirirugsa. Proposed IUCN conservation assessments are also given: Kaempferia nemoralis Insis. sp. nov. occurs in disturbed, open forest and is assessed as CR, whereas Kaempferia pascuorum Insis. sp. nov. occurs in short grassland and is assessed as EN.


Introduction
know their natural ranges. The centre of diversity is undoubtedly in the monsoonal parts of SE Asia, particularly Thailand and its immediate neighbours. South of Thailand, the diversity drops sharply with four species reported from Peninsular Malaysia, only one or two of them native (Holttum 1950). To the north, only fi ve species of Kaempferia extend to the tropical provinces of China, and are probably more often cultivated or naturalised than native ones (Wu & Larsen 2000).
It has been more than a century since the publication of the most recent monograph of all species of Kaempferia (Schumann 1904), and the most recent revision of the genus in Cambodia, Laos and Vietnam (Gagnepain 1908). Revisions of Kaempferia for the Flora of Thailand (T. Jenjittikul et al., in prep.) and in Cambodia, Laos and Vietnam (O. Insisiengmay et al., in prep.) are under way, and have already revealed considerably more species than were known to Gagnepain (1908) who recognised 13 species in Cambodia, Laos and Vietnam. In more recent accounts, nine species were recorded in Lao PDR (Newman et al. 2007), but an additional six have been described in that country in the last 12 years (Koonterm 2008;Picheansoonthon & Koonterm 2008, 2009bPicheansoonthon 2009;Phokham et al. 2013), and more are expected from Cambodia and Vietnam. Twenty-seven species are recognised in the current draft of the Flora of Thailand revision (Ruchisansakul, pers. comm.), including 11 described in the last 9 years (Nopporncharoenkul & Jenjittikul 2017Nopporncharoenkul et al. 2020;Phokham et al. 2013;Picheansoonthon & Koonterm 2009a;Picheansoonthon 2010Picheansoonthon , 2011Wongsuwan et al. 2015) and at least three more are to be described.
Many species in the genus are very poorly known taxonomically, mainly because it is so diffi cult to make informative specimens from these plants, which usually bear only one, extremely delicate and short-lived fl ower per plant each day of the fl owering period. Furthermore, the infl orescence is often held between the leaves and is a complex structure of bracts, bracteoles and a number of fl owers at different stages. Several species bloom at night and must be collected in darkness. Others bloom early in the rainy season, before the leaves appear, so to obtain all parts of the plant, two collections must be made a few weeks apart. Therefore, herbarium collections are often of relatively little use to the taxonomist and must be supplemented by living material.
Morphologically, Kaempferia is distinct from other genera of Zingiberaceae. It is classifi ed in the subfamily Zingiberoideae tribe Zingibereae which comprises genera with large, petaloid lateral staminodes, about the same size as the lip. The species of Kaempferia are small herbaceous perennial plants, some with two leaves appressed to the ground, others with erect leaves to about 70 cm tall. The strongly zygomorphic fl owers consist of the usual parts found in Zingiberaceae, an inferior ovary, tubular calyx with three lobes, fl oral tube with three corolla lobes, a labellum, two lateral staminodes and a single fertile anther with two thecae which hold the style so that the stigma is presented just above the anther. The diagnostic character of the fl owers of Kaempferia is the deeply bilobed labellum and large lateral staminodes which are often held in a single plane so that the open fl ower resembles, at fi rst glance, a tetramerous, salverform fl ower.
A thorough account of the history of infrageneric classifi cation of Kaempferia is given by Kam (1980), and the correct generic name for the African species by Burtt (1982). The fi rst classifi cation of the species of Kaempferia into infrageneric taxa was made by Horaninow (1862) who described two taxa, Kaempferia [unranked] Soncorus and Kaempferia [unranked] Protanthium. The fi rst of these was described as 'fl ores centrales' and the second as 'fl ores praecoces, ante folia e caudice projecti' which is to say that species in the Soncorus group produce their infl orescences terminally on the leafy shoots while those in the Protanthium group produce them early in the growing season, before the leaves, arising from the rhizome. Horaninow placed Kaempferia galanga L. with seven other species in his Soncorus group and K. rotunda L. with two other species in his Protanthium group.  (Turland et al. 2018, Art. 22.2). Insisiengmay et al. (2018) were only able to locate a single element of original material of K. rotunda, and it did not match the written description in the protologue, so a proposal to conserve the name with a conserved type was made. This proposal, number 2581, has been recommended by the Nomenclature Committee for Vascular Plants (Applequist 2020).
During fi eldwork in Cambodia, Laos and Vietnam in 2016 and 2017, directed towards a revision of Kaempferia in these three countries, we found additional undescribed taxa. Here, we describe two new species, Kaempferia nemoralis Insis. sp. nov. and Kaempferia pascuorum Insis. sp. nov., the fi rst known only in Cambodia, the second distributed in southern Lao PDR and Cambodia. We compare the morphology of these new species to closely related taxa and we also propose a conservation status of each one using IUCN criteria.

Material and methods
A revision of Kaempferia in Cambodia, Laos and Vietnam formed part of the PhD thesis of the fi rst author (Insisiengmay 2019). All names applied to species of Kaempferia in these and surrounding countries were examined. Protologues were gathered and specimens, including types at BK, BKF, BM, E, HNL, K, P, QBG, SING and VNM were studied. Herbarium codes follow Index Herbariorum (Thiers, continuously updated). Specimens were collected during fi eld expeditions in Cambodia, Laos and Vietnam from April to August 2016 and May to September 2017. While most collections could be determined to an existing taxon, a small number of collections did not match any herbarium material examined. Among these collections, were the specimens described as two new species below.
Each collection included: fl owers and infl orescences in ca 70% alcohol, dried herbarium specimens, rhizomes for cultivation and leaf material in silica gel for molecular systematic study. A complete set of herbarium vouchers and the living collections were deposited at the National Herbarium, Muséum national d'histoire naturelle (P). The species descriptions are based on the spirit material because dried herbarium specimens lack three-dimensional structures and undergo changes in dimensions of parts of the plants which are very important for species description. The botanical terminology follows the Kew Plant Glossary (Beentje 2016).
IUCN conservation assessments of both species have been made using the Guidelines for Using the IUCN Red list categories and Criteria ver. 3.1 (2012) and ver. 13 (2017). Infl orescences and fl owers similar to those of K. rotunda (Kaempferia subg. Protanthium) by the presence of white staminodes and size of labellum but distinguished by the following characters: presence of peduncle, fl oral tube longer, 95 mm long (vs 50-55 mm long in K. rotunda), labellum purple with white line at centre, anther crest obovate, bifi d, apex irregularly rounded and ovary glabrous, the vegetative parts differ by the shape and indumentum of the leaf blade, and absence of a petiole.

Etymology
The specifi c epithet is from the Latin 'nemoralis', meaning 'of woods'. The only known locality is in open forest near a small stream.

Distribution and habitat
Only known from the type locality where the plants were found growing in dry dipterocarp forest, near a stream, in moist, sandy soil at low altitude, 74 m.

Conservation status
Proposed IUCN conservation status: CR. AOO = 4 km 2 , this species is known only from the type locality which is near a path at the edge of a village where tractors and herds of cattle pass frequently. The area is not protected by law. The number of mature individuals is less than 20.

Notes
Other species of Kaempferia, not yet determined, were also collected at the type locality of Kaempferia nemoralis sp. nov. These species clearly differ from Kaempferia nemoralis sp. nov. by having their leaves fl at on the ground and by a number of characters of the fl oral parts.
A high-resolution image of the type specimen will be deposited at RUPP, the National Herbarium of Cambodia. Normally, a type specimen would be deposited in the country of origin, but there is very little type material of Kaempferia nemoralis sp. nov. and no paratypes, so it has been agreed with the curator of RUPP that it is better to keep the types at E and P where the conditions for long-term conservation, especially of spirit material, are much better.
The collections at the herbaria listed in Material and methods were searched thoroughly, but no material of Kaempferia nemoralis sp. nov. was discovered.

Etymology
This species epithet is derived from the Latin 'pascuorum' (of pastures), referring to their habitat.

Distribution and habitat
Southern Lao PDR and Cambodia, paddy fi elds or in very open areas, in sandy soil.

Conservation status
Proposed IUCN status EN B1, B2, a, b(iii). EOO = 480 km 2 , AOO = 12 km 2 . This species is only known at three locations near the Cambodian-Lao border, none of which is protected in law. The main threat in Lao PDR comes from agriculture, particularly the creation of pathways to and between fi elds. The Cambodian location is within a built-up area in Siem Pang town. It may be developed in future. The number of mature individuals found at each location is less than 20.

Discussion
This paper describes and illustrates two new species of Kaempferia, recently discovered in Cambodia and Lao PDR, adding to the overall biodiversity of these countries. A key is provided to distinguish the two new species from the other species known in these countries. The Vietnamese species of Kaempferia are not all included in this key because of the number of taxonomic uncertainties which remain. Further work is under way to produce a revision of Kaempferia in Cambodia, Lao PDR and Vietnam, including a molecular phylogenetic survey of the genus. More fi eld collections are needed to complete our studies of poorly known species and to discover new taxa for which we have not yet obtained complete material. An assessment of the variation of species across their ranges is also required. In conclusion, our taxonomic and fi eld work have already enriched botanical knowledge and collections, but more work is urgently needed in Cambodia, Lao PDR and Vietnam which are experiencing a high rate of deforestation and land conversion (Lang 2001).