Variation of fruits in different species of Litsea Lamarck (Lauraceae) in Sikkim, India Trina Bhuinya and Sobhan K. Mukherjee Taxonomy and Biosystematics Laboratory, Department of Botany, University of Kalyani, Kalyani 741 235, WB, India E-mail : trina.bhuinya@gmail.com; sobhankr@yahoo.com Abstract Fruit characters in Litsea Lamarck are unique and can be used to identify the species. Fruits and infructescence of 13 species of Litsea from Sikkim have been studied and a dichotomous, user-friendly field identification key has been constructed for their identification. Key words: Litsea; Fruit variations; Sikkim INTRODUCTION Lauraceae comprise of c. 32 genera with 2500 species occurring in the warm temperate regions of Asia, Australia, North and South America (Mabberley 1997). The genus Litsea Lamarck repre- sented with 45 species in India of which 13 species are known to grow in Sikkim. Of these, L. glutinosa and L. monopetala are most widely distributed up to 1200 m and 700 m respectively. Other commonly occurring species are L. cubeba [300 m to 1800 m], L. elongata [1800 m to 3100 m], L. laeta [300 m to 900 m], and L. salicifolia [900 m to 1600 m] are also growing in compara- tively low altitude areas. Species growing in high altitude areas like L. kingii. and L. sericea have been collected from above 2000 m and up to 3000 m. Other species known to grow in Sikkim Himalayas are L. albescens (1200 m to 2100 m), L. doshia (1300 m to 2700 m), L. hookeri (400 m to 900 m), L. lancifolia (600 m to 1200 m), and L. panamanja (300 m to 700 m). The plants are dioecious and are mostly identified by the four-celled anthers in male flowers. Often, the fruiting specimens remain unidentified due to absence of flowers. But the fruits in the species of Litsea are unique and can be used to identify the female plants. The shape and size of fruits, nature of the infructescence, characters of perianth-tubes and peduncles are of immense value for identifying its different species. The variations in the fruits of Litsea in Sikkim are studied and documented for the first time in the present paper. MATERIALS AND METHODS Field surveys were conducted in Sikkim during 2004 to 2007 to collect specimens of Litsea Lamarck. Along with this, herbarium specimens were examined in CAL, BSHC and in the Herbarium of Llyod Botanical Garden at Darjeeling. The fruiting characters were noted and compared to study the difference among the species. An artificial key was prepared to identify the species in the field condition as well as in the herbaria. OBSERVATIONS AND DISCUSSION Fruits of Litsea Lamarck are berries those are seated on a persistent and enlarged perianth-tube. The shape, size and architecture of the perianth-tubes vary in different species. The flowers are perigynous, seated on a perianth-tube (hypanthium), with or without lobes. In fruits, the perianth- tubes enlarge more quickly than the ovaries. Hence, the berry is completely enclosed in a perianth- cup when young. At a later stage, the berry may over-grow the cup. Accordingly, the perianth-cup may be almost flat or unaltered, plate-like or slightly developed, saucer-shaped or cup-shaped or obconical, covering more than half of the length of the berry. Pleione 4(2): 247 - 249. 2010. ISSN: 0973-9467 © East Himalayan Society for Spermatophyte Taxonomy