Be. 
À restoration-shoot grown up through the sand from a 
buried shrub of Alhagi had its subterranean part beset with 
scale-leaves and with a yellow coating which was thick and 
spongy to the touch. When cut through the coating proved 
to be a thick layer of cork (fig. 50, D, E), formed from 
a phellogen in the cortex; this was double the thickness of 
pith, wood and inner cortex together. All the cells had 
exceedingly thin corky walls, easily torn and all empty and 
dead. Inside such an air-filled case the growing shoot must 
be well protected. 
Heliotropium dasycarpum Ldb. 
An undershrub occurring in the clay-desert. It has 
leaves 1 to 2 centimetres in length, coated with stiff hairs; 
the foliage is so open that the whole plant is transparent. 
The flowers appear in June and July and evidently only the 
lower flowers of the scorpioid cyme produce fruit. The 
achenes are long-haired and haïd-shelled. 
The leaf is almost isolateral in structure. The epidermis 
is one-layered with stomata on both surfaces and not sunk. 
Both surfaces are coated with hairs most of which are bent 
to one side while some are short and somewhat dome-shaped. 
The cuticle extends over all the epidermis as a warty 
covering. The hairs arise from large thin-walled epidermal 
cells which contain stratified cystoliths, the so-called hair- 
cystoliths (see SOLEREDER 1899, p. 632, fig. 127; the hairs 
mentioned here are similar to fig. B). The upper face of the 
leaf has one layer of long palisade cells, the lower face two 
layers of shorter ones. Grouped around the veins in the 
middle are some isodiametric or slightly oblong cells, trans- 
lucent or containing a little chlorophyll. 
Frankenia hirsuta L. (= F hispida D.C). 
This species occurs in comparatively moist localities and 
as a rule on a saline soil. It has decumbent, lignified bran- 
ches. The leaves are about half a centimetre long, revolute, 
with scattered hairs and with grains of salt. The small red 
flowers may be found still open in July. 
