2. The north-western area is best marked in Sind and the Punjab, where the climate is very dry (the rainfall averaging less than 15 in.), and where the soil, though fertile, is wholly dependent on irrigation for its cultivation. The flora is a poor one in number of species, and is essentially identical with that of Persia, southern Arabia and Egypt. The low scattered jungle contains such characteristic species as _Capparis aphylla_, _Acacia arabica_ (babul), _Populus euphratica_ (the "willows" of Ps. cxxxvii. 2), _Salvadora persica_ (erroneously identified by Royle with the mustard of Matt. xiii. 31), tamarisk, _Zizyphus_, _Lotus_, &c. The dry flora extends somewhat in a south-east direction, and then blends insensibly with that of the western peninsula; some species representing it are found in the upper Gangetic plain, and a few are widely distributed in dry parts of the country.
3. For the Malayan area, which Sir Joseph Hooker describes as forming "the bulk of the flora of the perennially humid regions of India, as of the whole Malayan peninsula, Upper Assam valley, the Khasi mountains, the forests of the base of the Himalaya from the Brahmaputra to Nepal, of the Malabar coast, and of Ceylon," see ASSAM, CEYLON and MALAY PENINSULA.
4. The western India type is difficult to characterize, and is in many respects intermediate between the two just preceding. It occupies a comparatively dry area, with a rainfall under 75 in. In respect to positive affinities, Sir Joseph Hooker pointed out some relations with the flora of tropical Africa as evidenced by the prevalence of such genera as _Grewia_ and _Impatiens_, and the absence, common to both countries, of oaks and pines which abound in the Malayan archipelago. The annual vegetation which springs up in the rainy season includes numerous genera, such as _Sida_ and _Indigofera_, which are largely represented both in Africa and Hindustan. Palms also in both countries are scanty, the most notable in southern India being the wild date (_Phoenix sylvestris_); _Borassus_ and the coco-nut are cultivated. The forests, though occasionally very dense, as in the Western Ghats, are usually drier and more open than those of the Malayan type, and are often scrubby. The most important timber trees are the _tún_ (_Cedrela Toona_), _sál_ (_Shorea robusta_), the present area of which forms two belts separated by the Gangetic plain; satin wood (_Chloroxylon Swietenia_), common in the drier parts of the peninsula; sandal-wood, especially characteristic of Mysore; iron-wood (_Mesua ferrea_), and teak (_Tectona grandis_).