CONTRIBUTIONS TO THE FLORA OF BHUTAN: THE MONOCOTYLEDONS A collection of papers submitted to the University of Edinburgh for the degree of Doctor of Philosophy (by Research Publication) Henry J. Noltie Royal Botanic Garden Edinburgh June, 2000 Abstract The published work submitted for consideration for the degree of Ph.D. (by Research Publication) consists of two parts of the Flora of Bhutan, describing the monocotyledons (some 942 species) with the exception of Orchidaceae. Together with these are ten precursor papers relating to these parts of the Flora: the papers include descriptions of new species, nomenclatural discussion (including typifications) and phytogeographic information. The critical review gives the historical background for the whole Flora project, together with the methods used in my own contribution and some of my more interesting findings. An enumeration of new taxa described, and new combinations made, is given in an appendix. CONTENTS Introduction 1 What is a Flora? 2 Brief outline of Bhutan 3 Flora of Bhutan: the history of the project 5 Funding 13 Storage of data 13 Illustrations 14 Biogeography 14 Introduced and cultivated plants 17 History of exploration 18 My own work 28 Fieldwork for monocots 33 Practical uses of the Flora: examples from the monocots 35 The future 36 Conclusions 38 Acknowledgements 39 References 40 Appendix 1. Publications submitted for Ph.D. 46 Appendix 2. New taxa and combinations 48 Appendix 3. Floristic elements in Gramineae 50 Appendix 4. Contributing authors and artists 51 CRITICAL REVIEW Introduction This 'critical review' is supposed to describe the aims, objectives, methodology, results and conclusions of the published work submitted. Since the project is fundamentally descriptive in nature, it will not adopt this format, which is suited to a more experimental methodology. It is also inappropriate in that my own work forms part of a much larger project, and the purpose of this review is primarily to put my contribution to the whole work into context. I have written two parts of the Flora of Bhutan (with some contributions from others, separately attributed in the volumes), covering the monocotyledons excluding Orchidaceae. In submitting this work to be considered for a doctorate, I am acutely aware that this represents only a contribution towards a much greater whole. In achieving this contribution I am hugely in the debt of others, especially to David Long and the late Andrew Grierson, who jointly initiated the project, and undertook the substantial groundwork required for such a major floristic work. Nevertheless, my contribution stands as part of a team effort, and has validity as a section of work in its own right. It includes one very large family, the Gramineae, the second largest in the Flora with 125 genera and 388 species (Noltie, 1999a, b; 2000a, b), and, Carex, the third largest genus in the Flora, with 73 species (Noltie, 1993a, 1994a). In putting my contribution into context, it is necessary to explain something of Floras in general, and the particular history of this one - which is unusual in many respects. Explaining the cultural, scientific and political background to this Flora may be a useful contribution to understanding the difficulties that can attend Western attempts to document the biodiversity of a developing country. 1 880 900 920 / - LI BHUTAN L)A Rj EELG CHINA E: - \INDIA FIG. I AREA COVERED BY THE FLORA What is a Flora? A Flora is, at its simplest, an inventory of plant species occurring in a defined geographical area; within this basic definition there exists wide scope in terms of the information contained, style, etc. The Flora of Bhutan was designed to be used in the field, without the backup of a large herbarium or library. The arrangement of families follows the Englerian system. Introduced and cultivated plants are included, in addition to native ones. The descriptions are short, and minimal synonymy is given (chiefly that relating to the Flora of British India, still the standard floristic text for the region). Keys are given to genera within families and to species within genera. Local names and uses are included wherever possible. Distribution within the country is given, along with ecological details (altitudinal ranges and habitats). Representatives of all the families are illustrated by means of line drawings. Not included in the Flora are citations of specimens or types, the places of publication of names, or distributions of species outwith the area. None of these were thought to be of much use in Bhutan, in the absence of a herbarium or library, though in retrospect, and especially given the amount of research into nomenclature and distribution, some of these are perhaps regrettable omissions. The existing floristic literature relating to Bhutan is extremely sparse; a few nineteenth century records (those of William Griffith) are included in the Flora of British India (1872--97), and there are some more recent floristic lists (e.g. Hara, 1971; Subramanyam, 1973). Such a'lack of primary information for an area of major phytogeographic significance has been a severe lacuna in world floristic literature, and, at the local level, in applied fields such as conservation, ethnobotany and the sustainable use of plant resources (for example in traditional medicine). In filling this gap, an authoritative floristic treatment of the plants of Bhutan will enable broader views to be taken of the distribution and ecology of S Asian taxa. It is vital, therefore, to stress the fundamental importance, and pressing need for such a Flora. In more recent PJ times, such cataloguing of biodiversity has become a legal requirement, as one of the conditions arising from signing the Convention on Biological Diversity, which the Royal Government of Bhutan (RGOB) did on 11th June, 1992. A common criticism of Floras is that they are artificial in the sense that they describe the plants of arbitrary, or at least 'non- natural' areas. This is undoubtedly true, but does not make them unimportant or without value. The question of artificiality of boundaries is true in the case of Bhutan: although it is naturally defined in terms of its northern and southern boundaries (the summits of the high Himalaya and the northern edge of the Bengal plain respectively), the eastern and western boundaries are more or less arbitrary. The inclusion of Sikkim and Darjeeling (originally on the grounds that their plants were better known, being more extensively collected) makes the area covered by the Flora more representative of the E Himalayan floristic province than if it had been restricted to the political country of Bhutan (FIG. 1). In my own work I have been very conscious of the dangers of looking too narrowly and have paid especial attention to China in determining species limits, and also in the fields of literature and nomenclature. Having been based at the Royal Botanic Garden Edinburgh (RBGE), with its unique Chinese collections of herbarium specimens and literature, has been a significant advantage. This would not have been possible if, for example, the work had been carried out at Calcutta or other apparently suitable bases. Brief outline of Bhutan It seems appropriate to describe here, very briefly, something of the physical and geographical background to Bhutan since this accounts, in a large degree, for its botanical interest. This is not the place to go into detail, as this is provided in the summaries in the first volume of the Flora (Grierson & Long, 1983); valuable information is also supplied in the recent Atlas of Bhutan (LUPP, 1997). 3 20 0 20 40 60 Kilometres ( / 7554m . 7 . —28 KuIaKangri / ° ChomoLhari 7314 oI I / he Punakh / / THIMPHU TOng ~Wangdi Paro Phodrng mth ang , Ganr, C" Tashigang 0 0 Z' . Chukka —27 c: Ile c DeothanJ Phuntaholing ayiegphug \ /2 89 90 9I 92 FIG. 2 MAP OF BHUTAN Bhutan (FIG. 2) is a small kingdom of 40, 077 sq. km, situated in the East Himalaya. It lies between the longitudes of 88°45' and 92'10'E, and the latitudes of 26°40' and 28'21'N. Politically it is sandwiched between China (Tibet) to the north and north west, and India (the States of West Bengal and Arunachal Pradesh) to the south west, south and east. The land rises very steeply from south to north, in a distance of under 175km, the Bengal plain being at about 200m, and the large Himalayan peaks reaching over 7500m. A series of river valleys and ridges run north to south throughout the country. These valleys vary greatly in depth, the deeper ones enabling subtropical vegetation to enter far into the interior of the country e.g. north of Punakha. Some, such as the Manas, are very dry and desert-like in their middle courses. The dominant climatic feature of the E Himalaya is the summer monsoon, which brings very large amounts of precipitation between April and October. Useful figures are given in Eguchi (1987). The climate is more variable than one might expect, given the size of the country, due mainly to the extremely varied topography. Rainfall is greatest in the southern foothills which receive the brunt of the moisture- laden winds coming from the Bay of Bengal, so that the annual precipitation at Phuntsholing on the Indian border is 4222mm (wettest month July, with 1000mm). The deep N-S valleys are much drier, so, for example, Thimphu only about 70km (as the crow flies) to the north receives 597mm of rain per year (wettest month August, with 150mm). The eastern valleys are drier still, for example, the annual rainfall at Mongar on the Kuru Chu is 518mm. Temperature also varies greatly - from the subtropical climate of the southern belt (with small seasonal fluctuations) - to temperate in the central zone - and extreme alpine in the north (the latter two with much greater seasonal fluctuations).