NOTES RELATING TO THE FLORA OF BHUTAN: XX Lloydia (Liliaceae)

being synonymous with L. serotina; L. yunnanensis is reported for the first time from the E Himalaya; L. delicatula Noltie sp. nov. is described; L. mairei and L. serotina var. parva are discussed.


INTRODUCTION
Until recently our knowledge of this attractive genus of alpine bulbs in the E Himalaya was extremely poor. This was due, at least in part, to the fact that they make poor herbarium specimens. Old specimens frequently lack colour notes, and as both white and yellow tepals fade to a dull brown it can be impossible to distinguish between them after several decades. Even flower posture is difficult to deduce from herbarium specimens in the absence of notes. The most important limitation of dried specimens concerns the nectary, which may be difficult or impossible to observe, and descriptions of presence or absence based only on herbarium material are probably not reliable. Hooker (1892) evidently despaired and included all Himalayan forms (including a perfectly good species he had himself described earlier) in the single species L, serotina; by the time he wrote this account, he had evidently forgotten his experience in Sikkim of almost 50 years earlier. Hara (1966) was the first to draw attention to the diversity occurring in the E Himalaya, based on his field experience in Sikkim and E Nepal, though without coming to very firm taxonomic conclusions. It was not until 1974 that he described the highly distinctive E Himalayan, yellow-flowered plants as L.flavonutans (having previously identified them as the ChineseL. delavayi Franchet). The author was fortunate to be able to study two of the taxa discussed below in W Sikkim on the Edinburgh Expedition to Sikkim and Darjeeling (ESIK) during the summer of 1992.

A. Large white-flowered species (L. serotina, L. himalensis and L. yunnanensis)
L. himalensis Royle was described and illustrated by Royle (1840) from the NW Himalaya, and distinguished from L. serotina (then known as L. alpina) on small and insignificant characters; it has, therefore, generally and correctly been included under the latter. The type of L. himalensis should be in Royle's herbarium at LIV and was seen by Dasgupta & Deb (1986). Recent enquires, however, have failed to locate it (A. Gunn, pers. comm.). However, the published illustration is of high quality and in Hooker's herbarium at Kew there is what is almost certainly a syntype labelled 'Lloydia himalensis Royle 111. t. 93. NW India. Hb. Royle'. All specimens on this sheet (except one which is L. longiscapa Hook, f.) clearly belong to L. serotina. In recent years, however, the name L. himalensis has been reinstated to cover a rather distinct E Himalayan plant with long tepals and a very long style. Hara (1966) did so informally and was followed (at least the E Himalayan plants cited) by Dasgupta & Deb (1986), who also noticed the trifid stigma of this taxon. This usage, however, is quite contrary to the description, illustration and specimens of L. himalensis and the identity of this taxon must be elucidated.
This proves to be another case where the answer is found by looking east to China, the plant concerned being L. yunnanensis Franchet (Fig. 1). This species was described from the Tsang Shan mountains near Tali in Yunnan. The original description is rather inadequate and places great weight on the trifid stigma but does not mention the tepal characters or lengths of anthers and style which are useful and more reliable in distinguishing it from L. serotina. Herbarium studies have shown this taxon to occur as far west as E Nepal, apparently favouring acid rocks (granite in China) and occuring from 3000-4200m. The degree of production and revolution of the stigma lobes is in fact variable.  Hara (1966) reported L. serotina-like, plants similarly lacking a nectary from Sikkim, but doubted if they should be separated from L. serotina.
It seems likely that Handel-Mazzetti's record of L. mairei should be referred to L. yunnanensis, under which species it has, in fact, been sunk by recent Chinese authors (Chen, 1980). Examination of the type of L. mairei at E, however, suggests that it is a distinct species and in some ways intermediate between L. yunnanensis andL. serotina, having the tepal shape, apparent absence of nectaries when dry and long style of the former, but small tepal size, shorter anthers and unlobed stigma of the latter; it sometimes produces two flowers per scape and differs from any material seen from E Himalaya.

B. Dwarf alpine forms
Hooker (1892) was the first to note 'a very minute tufted state' of L. serotina in Sikkim. Examination of his herbarium specimens reveal them to be a mixture of two miniscule taxa which have commonly been confused in the E Himalaya ever since.

L. serotina var. parva
The first taxon is merely a dwarf variety of L. serotina (L.) Rchb. which can be referred to var. parva (Marq. & Shaw) Hara; a syntype of this variety has been studied (Rong-chu (Tumbatse), SE Tibet, Kingdon Ward 5798, E). There has been some confusion as to whether or not nectaries are present on the tepals of this variety. Hara (1971), when raising parva from the rank of forma to variety, states that it does not have a transverse fold (i.e. nectary) above the base of the inside of the tepals. This absence would distinguish it from L. serotina var. serotina, which always has such a fold. However, after examining small specimens of L. serotina it seems the absence of nectaries is at least sometimes more apparent than real. The closeness of the nectary to the tepal base makes it often very difficult to observe (virtually impossible in the dry state and scarcely easier in boiled-up material). Nectaries are definitely present in the syntype cited above. Krause evidently thought of treating this taxon at specific rank at some stage since a Chinese specimen (Litang River divide, 14-15,000ft, Kingdon Ward 4078, E) bears the manuscript name 'L. wardii Krause n. sp.' in his hand -but this seems never to have been published.
Distribution: This species appears to be restricted to the E Himalaya, occurring from C Nepal to NE Bhutan.