CERTAIN DICOTYLEDONOUS AND CONIFEROUS LEAVES. 263 
GLYPTOSTROBUS HETEROPHYLLUS, Endl. 
The recent material of this leaf was supplied from the herbarium in the 
Botanical Department of the British Museum (Hb. Hance, 5276). 
External Characters —Leaves persistent, and rather variable in form, 
similar in habit to those of Tawodium, but not two-ranked, spiral, closely 
packed, decurrent, and somewhat falcate, with the arch of the sickle bending 
outward, not inward, as in Sequoia and Araucarites. The tip is narrowed 
and acute. 
Cuticular Structure (Pl. 21. fius. 37, 38). 
Stomatal Apparatus.—The stomata show a banded structure and occur on 
both sides. A band consists of about four irregular rows of stomata, which 
are sunk beneath large pits. The poral axes are very variable in direction, 
but many are orientated parallel to the long axis of the leaf. The pores are 
bounded by four, five, or six deeply staining cells, but five is the commonest 
number. The arrangement of the encircling cells is variable. When four 
surround the pore, they do not show the definite grouping Florin describes 
for T. distichum, i.e., two disposed longitudinally and semilunar in shape, 
and two disposed transversely, Frequently two occur on each side, the 
junction in the longitudinal direction being very narrow. Occasionally a 
cell closing in the pore longitudinally will be somewhat elongated vertically. 
This is comparable with the very elongated longitudinal cells bounding the 
pore in Taxodium distichum, in the vertical direction. The stomata in a band 
are very close, and frequently no epidermal cell separates two poral rings of 
adjacent lateral rows. At the most they are separated by one or two cells. 
Epidermal Cells are elongated parallel to the long axis of the leaf. The 
cross walls show varying degrees of obliquity and are sometimes curved. 
This obtains also in Taxodium europeum, but to a much less extent in 
Taxodium distichum, though it also occurs there. 
COMPARISON BETWEEN THE LEAVES OF 
Taxodium europæum. T. distichum. Glyptostrobus heterophyllus. 
External Charactere. 
Leaves imbricated, closely | Leaves deciduous, distichous, | Leaves persistent, spiral, 
adpressed, decurrent, and| green, not scale-like. closely packed, decurrent. 
alternate. 
Leaves recurved, small, acute | Uninerved, light green | Leaves recurved. 
or obtuse. Size and form | needles. - 
somewhat variable, scale- 
like or not. 
Average length of leaf. 
2:2 mm. &8 mm. 8 min. 
Average width of leaf. 
'57 mm. 1:0 mm. ‘8 mm. 
