Page:The Journal of Indian Botany.djvu/706

240 THE JOURNAL OF INDIAN BOTANY. out its masses of pinkish flowers and reminds one of the blossoming apple tree. Erythrina suberosa dots the woods with scarlet, Jndigo- fera atropurpurea and Ougeinia dalbergioides with lavender, and Caesal- pinia sepiaria with golden yellow. A number of early blooming herbs, such as geraniums and violets now come out. The deciduous trees of the oak forest develop their leaves until the beginning of the mon- soon while the trees of the monsoon forest become increasingly leafless until about the same time. The highest recorded temperature is 92° in May, 1921.

The herbaceous vegetation at this level may be considered as constituting three fairly distinct seasonal groups. With the spring rise of temperature come mainly representatives of temperate zone families, such as Ranunculaceae, Gruciferae, Caryophyllaceae, Viola- ceae, Geraniaceae, Bosaceae, Crassulaceae, and Compositae. With the monsoon come mainly representatives of tropical families, such as Begoniaceae, Gesneriaceae, Orchidaccae and Scitaminaceae. In the cooler and less humid conditions following the monsoon come repre- sentatives of families which largely constitute the autumnal vegetation of the temperate zone, such as Compositae and Labiatae.

The monsoon forest grows over the whole area from the foot of the hills up to the crest of the ridge, about 4500 ft. high, which borders the Bhim Tal and Sat Tal lake valleys on the south, and occupies many of the exposed slopes and ridges within the valley. This is the typical forest described by Schimper (10) for tropical dis- tricts with pronounced dry seasons.

There are two types of this formation determined by altitude. From the base of the hills to about 3000 feet is a forest dominated by Shorea robusta, but having as important elements Semecarpus anacar- dium and Bassia butyracea> This type does not extend to the altitude of Sat Tal valley. It contains a good number of tree species, but Shorea is the climax form, producing r an almost pure forest of tall straight black-barked trees which is able to hold its own against in- vaders. From 2500 to 4500 (in suitable exposures as high as 5500) feet the climax forest is marked by three species of Bauhinia. B. va- riegata is a spring-blooming tree, B. retusa an autumn blooming tree and B. Vahlii, the elephant creeper, a gigantic woody twiner. There is a good sprinkling of other legumes such as Erythrina, Indigofera. Oligemia, Dalbergia, and Caesalpinia. This might be called the Le- gume forest or better, since the Bauhinias occupy a climax position, the Bauhinia forest. It contains numerous other deciduous trees such as Grewia, Nyctanthes, Mallotus, Sapium, Odina. This forest is found