208 
MORPHOLOGY 
Leaves. The leaf is very characteristic in form and venation (fig. 
465), the broadly wedge-shaped outline, often more or less lobed, and 
the forked veins resembling somewhat the leaves of maidenhair fern 
and suggesting the common name. The mesophyll has the peculiar 
character (transversely elongated and very loosely arranged cells) 
described under Cordaitales and Cycadales (p. 193). 
FlGS. 466, 467. Staminate strobilus of Ginkgo: 466, the clusters of strobili borne on 
dwarf branches; 467, a single strobilus, showing the character of the individual stamens 
(a stalk ending in a knob and bearing two pendent sporangia). 
Strobili. The strobili are monosporangiate, and the two kinds of 
strobili occur on different trees (dioecious). 
Staminate. The staminate strobili occur in loose catkin-like clusters 
borne on the dwarf branches (fig. 466). The sporophyll (stamen) con- 
sists of a stalk ending in a knob, from beneath one side of which two 
(sometimes three to seven) pendent sporangia are borne (fig. 467). This 
type of stamen suggests the epaulet type found among Cycadofilicales 
(see p. 184). The development of the sporangium is regularly eusporan- 
giate, as described under Cycadales (p. 194). 
