324 Transactions. 



(cl.) Rubus subpauperatus. 



A. LIFE-FORM. 



Members of this species are scattered throughout most parts of the 

 forest, and attain a size at least equal to that of any other of the lianes. 

 Their foliage may be expanded upon the branches of the highest trees, and 

 between the foliage and the ground, the stems stretching" up, as in R. aus- 

 tralis, beside the bare stems of supporting taxads, attain considerable thick- 

 ness ; sometimes they are as much as 16 cm. in diameter, and are thickly 

 covered with rough, dark-brown, scaly bark (Plate XXV, fig. 1). Even 

 from such stems as these, adventitious shoots arise, which in the more open 

 situations do not grow to a great length, but give off numerous leafy 

 branches, so that the adult stem is often covered for a considerable portion 

 of its entire height by these hanging leafy festoons. Among the low-lying 

 trees and shrubs the liane, as in other species of Rubus, scrambles over 

 the support and among the branches. In the more shaded stations the 

 internodes are longer than those of more exposed plants, and from stems 

 traiUng along the ground numerous adventitious roots arise. Beyond the 

 outermost fringe of forest-trees R. subpauperatus forms dense masses 1-2 m. 

 in height. The plants here very quickly cover any low-growing shrub with 

 their wiry interlacing branches, and spread over extensive areas. This is 

 due to the rapid elongation of their shoots, which may bridge the spaces 

 between adjacent shrubs, or which may trail along the ground, and thus 

 reach supports many metres distant. Both leaves and stems are thickly 

 beset with prickles, which by their grasping action are especially suitable 

 for this straggUng growth over low supports. Moreover, the prickles enable 

 the plants to use supports of greatly varying nature, such as branching 

 shrubs and trees, tree-trunks with rough bark, and even vertical rock-faces.* 

 The growth of plants in the open results in a shortening of the internodes 

 and excessive reduction of leaf-surface. This reduction appears to be corre- 

 lated with increased transpiration, for when a plant is exposed to southerly 

 winds the greatest reduction is on its south side, although this is shaded 

 from the bright sun. Again, when the prevailing winds are from the north 

 it is on the north side of the plant that the leaves are most reduced. 



B. LEAF. 



(i.) LeaJ-form. 



(a.) Shade Leaf. — ^Leaf 3-5-foliate ; terminal leaflet, lamina 6-8 cm. 

 long ; lateral leaflets sHghtly shorter ; when 5-foliate the 2 basal leaflets 

 very small (2-3 cm.). Leaflets subcoriaceous, glabrous, linear-lanceolate or 

 linear, acute, base truncate or obtuse, margin serrate. Petiole 7-9 cm. ; 

 terminal subpetiole 3-4 cm., but other subpetioles at most 5 mm. Prickles 

 numerous on back of petioles, in smaller numbers on subpetioles and mid- 

 ribs. 



(6.) Sun Leaf. — Plan of structure similar to that of shade leaf, but much 

 smaller. Lamina at most 5 cm. long, and very narrow ; but there is no 

 sharp distinction between the two types of leaves, for a single plant may 

 bear leaves which show all gradations in leaf-reduction. 



Tiii^ does not refer to Ricearton Busli 



