— 205 — 
rule they do not exceed 30 centimetres. They have a white 
bark, and are usually branched, branch-thorns arising in the 
leaf-axils; the leaf-base is thick and persistent. The branch- 
thorns are generally short, about 1 centimetre long, and often 
bear only two leaves placed low down near the base. The 
branch-thorns may, however, become longer and bear several 
pairs of leaves. The flowers arise from the base of the 
branch-thorns either in the axils of the two low-set leaves, 
or next year they form part of the rosette-shoots which appear 
in the axils of these leaves. On 
long branch-thorns the flowers may aus År DER 
also arise higher up. ar / | 
The year-shoots generally ter- D PR enr. 
minate in a thorn; their distal part Ä ÆRE 
always seems to die away. AMIE CIE 
They flower during summer. ICE à 
The leaf is isolateral in struc- f (C7): 
ture. There are stomata on both \& JE \ NER 
sides, generally flush with the sur- BERN VE. 
face but some of them are slightly | i: oh 
raised and below them is a group \. 
of cells, 2—4 on each side, which Ve 3) 
are round and devoid of chloro- SS 
phyll; throughout the rest of the Fig. 45. Lycium ruthenicum. 
leaf these cells are wanting (fig. 45). Part of ies in transverse sec- 
ion. X 203. 
The palisade tissue is 2—3 cells 
thick, and towards the interior it merges gradually into a 
large-celled aqueous tissue containing a slight amount of 
chlorophyll. The veins which lie a little nearer the upper 
side than the lower, have bundles of bast on both sides and 
here are found a few perfectly translucent cells. 
Nitraria Schoberi L. 
A shrub, barely one metre high which prefers the clay- 
desert. The bark is white, the leaves are thick and spath- 
ulate with short hairs, and are placed 2—4 together on a 
small cushion, with small scales between them. The leaves 
