440 INTRODUCTION TO PLANT GEOGRAPHY [CHAP. 



though varying in appearance from an impoverished form of the 

 latter down to the savanna-woodland type described below. Thus 

 in comparison with the rain forest, the monsoon forest tends to be 

 more open, with the trees farther apart and no such scramble of 

 all plants for light, while in the dry season {see p. 424) most trees 

 shed their leaves and the landscape takes on a ' wintry ' appearance. 

 The degree of defoliation depends, however, on circumstances — 

 particularly on the severity of the season and the proximity of water- 

 courses, along which trees tend to retain their foliage throughout 

 the year. Some evergreen trees persist except when the dry season 

 is particularly rigorous, and indeed there is apt to be relatively poor 

 correlation with the dry season, many species tending to produce 

 young leaves some time before it is over. This dry season is often, 

 moreover, the period of flowering, so that altogether the monsoon 

 forests at this time do not present as lifeless an aspect as do temperate 

 deciduous forests in winter. They do, however, resemble these 

 forests rather than tropical rain forests in that the trees have thick 

 bark, exhibit growth-rings in the wood, lack plank-buttresses, and 

 are usually not more than 12 to, at the most, 35 metres in height. 

 The trunks of the trees tend to be massive and fairly short, the 

 crowns being usually round and large, spreading widely from often 

 no great height above the ground. The branches are commonly 

 rather stout and gnarled, and the bark is typically fissured or scaly. 

 The community consists of three main tiers — the canopy which is 

 liable to be much interrupted, the undergrowth which tends to be 

 dense but to have small and hard leaves, and the ground or ' field ' 

 layer consisting mainly of more or less lowly herbs. The leaves of 

 the trees are usually thin but may be larger than those of the tropical 

 rain forest, as in the case of Teak (Tectona grandis). They function 

 only during the rainy season and so require no particular protection, 

 being commonly hygrophilous (possessed of features characteristic of 

 inhabitants of humid situations). The climbers are fewer and smaller 

 than in the rain forest, being often herbaceous, and vascular 

 epiphytes are normally found only in the canopy. Consequently 

 the undergrowth is often luxuriant, consisting of shrubby thickets (or 

 sometimes of tall tufty Grasses when the forest is immature, though 

 this is rather a feature of savanna-woodland). Bulbous and other 

 geophytes are also commonly present in considerable numbers and 

 flower in the dry season, whereas the shrubs tend to blossom at 

 the onset of the monsoon rains before the leaves appear, and many 

 herbs follow suit during the rainy season. Although the Teak 



