162 GENERAL BOTANY 



countries, open buds where the air is generally damp 

 and shrubs can be leafy and grow all the year round, 

 and the closed buds in colder climates where they need 

 special protection against the cold of winter, and 

 also in hot countries where vegetation is checked 

 by a hot dry season. 



2. Buds also differ in the way the leaves are 

 packed inside them. 



In MUSA (the Plantain) and CANNA, the whole leaf 

 is rolled up from one edge to the other. In 

 MARANTA one-half of the blade is smaller than the 

 other, and wraps round it. 



In QUISQUALIS (the Rangoon-creeper), ARTOCARPUS 

 (the Jak), FICUS (Banyan, Fig, Bo, etc.), and NELUM- 

 BIUM (Sacred-lotus), the leaf is rolled inwards from 

 both edges towards the mid-rib, the under surface 

 of the leaf being outside (see also fig. 39 ZlZYPHUs). 

 In NERIUM, POLYGONUM, and some palms the leaf 

 is also rolled inward from each edge, but the upper 

 side is outermost. 



One of the commonest arrangements is for the two 

 halves of the leaf, or leaflet, to be folded together along 

 the mid-rib, e.g. HIBISCUS TILIACEUS (fig. 6, p. 41). 



In the grass family the leaves are arranged in 

 two ranks, one on either side of the axis (not 

 spirally) and fit closely over each other. 



The fronds of ferns and the leaflets of CYCAS 

 (fig. 41) are peculiar in that they are coiled up along 

 their length, with the tip inside and gradually unroll. 



In some plants the leaf (or leaflet) is folded 

 along the main veins, and when just emerging from 

 the bud, shows only these veins towards the outside, 



