ADVERTISEMENTS:
The first comprehensive account of the plants of the Indian Arid zone was by Blatter and Hallberg (1918-21) who visited the districts of Jodhpin Jaisalmer and Barmer accompanied by T.S. Sabnis and D.B. Bulsara. They remarked that “the vast deserts of North Africa, Arabia, Central Asia, and even the New World have attracted the attention of many botanists, bill the Indian Desert has been sadly neglected.”
Now, however, western Rajasthan is perhaps one of the best botanically explored regions in India thanks to the interest shown by the various universities in Rajasthan, the Central Arid Zone Research Institute, Jodhpur and the Botanical Survey of India.
The first flora of western Rajasthan was published by Puri (1964) providing keys to the identification, along with short descriptions of the species. Bhandari (1978) published the “Flora of the Indian desert” which covers the districts of Jodhpur, Jaisalmer and Barmer.
ADVERTISEMENTS:
The revised edition of Flora of the Indian Desert (1990) has 682 species, 352 genera and 87 families, while comparing with the first edition there is an increase of 5 families, 32 genera and 88 species.
Shetty and Pandey (1977) in their “Studies on the flora of the Rajasthan Desert—A review” gave a history of botanical exploration and ecological studies undertaken in western Rajas than along with a synopsis of the floral composition and a comprehensive bibliography.
Composition of Flora:
The total Angiosperm flora of western Rajasthan, including both indigenous and naturalized plants, comprises of about 774 species and 48 varieties, belonging to 348 genera under 90 families. The table (9.1) gives the number of families, genera and species and their percentage under Dicotyledons, Monocotyledons and Gymnosperms.
The table shows that Poaceae is the largest family in both, number of species and genera in arid zone. Fabaceae and poaceae are the largest families of Dicotyledons and Monocotyledon respectively.
The following families have 8 or more genera:
The genera with 6 or more species are as follows:
Ipomoea L. (17 spp.), Cyperus L. (17 spp.), Indigofera L. (14 spp.), Heliotropium L. (14 spp.), Tephrosia Pers. (12 spp.), Euphorbia L. (12 spp.), Eragrostis P. Beauv. (12 spp.), Aristida L. (11 spp.), Convolvulus L. (9 spp.), Corchorus L. (8 spp.), Alysicarpus Neck, ex Desv. (8 spp.), Amaranthus L. (8 spp.), Sida L. (7 spp.), Cassia L. (7 spp.), Fimbristylis Vahl (7 spp.), Abutilon Mill. (6 spp.), Hibiscus L. (6 spp.), Zizyphus Mill (6 spp.), Solatium L. (6 spp.), Chloris Sw. (6 spp.), Digitaria Heist, ex Fab. (6 spp.) and Sporobolus R. Br. (6 spp.).
Monocotyledons are poorly represented except for Poaceae and Cyperaceae with 125 and 32 species respectively. The remaining 29 species of monocotyledons belong to 12 different families.
On the basis of only indigenous plants, there are 37 families with a single genus each and 24 families with a single species each. The ratio of the total number of genera to species is 1: 2.01 which is rather low in comparison to the corresponding ratio for the whole of India.
There is a general resemblance between the flora of Western Rajasthan and that of N. Gujarat as far as the dominant families are concerned, the first and second positions being occupied by Poaceae and Fabaceae respectively. Cyperaceae, however, aremoredominant in north Gujarat as compared to Western Rajasthan.
