SPERMATOPHYTES 
213 
of the southern hemisphere as are the pines of the northern hemi- 
sphere. The taxads in general are north temperate, Taxus (yew) being 
the most widely distributed genus. 
Sporophyte. The habit of the sporophyte 
body is familiar, in general being the branching 
habit established in Ginkgo and common to all 
conifers. In size the body ranges from large 
trees to straggling bushes. The mesarch type 
of bundle, characteristic of ferns, occurs in the 
stem of at least one species (a Cephalotaxus), 
but in most of them it is found only in the 
cotyledons, as in Ginkgo. The leaves are entire, 
as in all conifers, and range in breadth from 
the needles of Taxus to the broad blades of 
certain species of Podocarpus. 
Staminate strobilus. The staminate strobilus 
is always a distinct strobilus, enveloped by 
sterile bracts (as among Cordaitales, fig. 473). 
The sporophylls differ in form in the two tribes. 
Among the podocarps the sporophyll is bract- 
like, with two abaxial sporangia and a sterile 
tip (fig. 474); while among the taxads the spo- 
rophyll is peltate (epaulet type), as in Ginkgo, 
and bears a variable number of pendent spo- 
rangia (figs. 475, 476)- The development of 
the microsporangium is as usual among euspo- 
rangiates. The microspores (pollen grains) of 
the podocarps are peculiar in being winged, 
each pollen grain developing two winglike ex- longitudinal" sections of 
tensions from the exine, as among the pines. young staminate strobilus 
Ovulate strobilus. The ovulate strobilus is of r ^o-, showing the 
overlapping bracts (or) and 
much reduced, usually containing a single the position of the develop- 
terminal ovule. For example, in Torreya in s stamens (a). After 
(nearly related to Taxus) the ovulate strobilus CouLTER and LAND - 
resembles a simple ovulate flower, with four bracts (two decussate 
pairs) investing a terminal ovule (fig. 477). 
Ovtile. The integument of the ovule is of the ancient type, develop- 
ing three distinct layers (outer fleshy, stony, and inner fleshy); and a 
set of vascular strands traverses the outer fleshy layer, the inner set 
FIG. 473. Cross and 
