360 Transactions. — Botany. 



Art. XL1II. — The Stem-structure of some Leafless Plants of 

 New Zealand, with Especial Beference to their Assimi- 

 latory Tissue. 



By Miss A. C. Finlayson, M.A. 

 Communicated by Dr. Chilton. 



[Read before the Philosophical Institute of Canterbury, 3rd September, 



1902.'] 

 Plates XLV.-XLVII. 

 The plants whose stems were selected for investigation were 

 Discaria toumatou, Clematis afoliata, and three species of 

 Garmichaelia (C. flagclliformis, C. monroi, and G. nana). All 

 are natives of New Zealand. They form a descending series 

 with regard to their leaf -formation. Discaria toumatou has 

 small leaves in spring, which are not, however, adequate for 

 the work of assimilation ; in Clematis afoliata the leaves are 

 represented only by the long petioles ; while in Carmichaelia 

 flagclliformis there are practically no available leaves, only a 

 few very minute leaves being developed at the same time as 

 the inflorescences in spring ; in C. nana and C. monroi there 

 are no leaves at all in the adult plant. They are all included 

 by Diel's in his book, " Vegetations - Biologie von Neu- 

 Seeland " (arbeit aus dem Konigl. botan. Museum zu 

 Berlin, Leipszig, 1896), as pasture-land plants, found only 

 in the east and south-east. Clematis and Carmichaelia are 

 derivatives of the forest flora (p. 246). All except Clematis 

 afoliata, which is herbaceous and can climb by means of its 

 petioles, are shrubs (which may reach even the height of trees 

 in the case of Discaria toumatou in favourable localities). 

 Carmichaelia flag ellif or mis is a rather straggling shrub, which 

 partly lies on the ground and partly grows erect, and is much 

 branched ; C. monroi and C. nana are very dwarfy rigid 

 shrubs, growing close to the ground. Of the two, G. nana is 

 much the smaller. Discaria toumatou in exposed situations 

 only reaches the height of a bush, with a very prickly and 

 straggling appearance. All are characterized by their xero- 

 phytic structure. To quote Diels (p. 246): "Their xerophytic 

 structure is of striking intensity and difficult to understand in 

 comparison with other floras, if we recollect that even the 

 driest areas of New Zealand suffer under a less excessive 

 climate and less frequent droughts than middle Europe. Yet 

 the diminution of transpiration is not less in these bushes 

 than in the plants of dry steppes ; and habitually the many 

 species, so widely separated, systematically converge in an 

 extraordinary manner and agree in physiognomy with desert 

 vegetation." 



