278 PHYLUM XIII. STROBILOPHYTA 
long-lived tree, rooted below, and bearing green (mostly 
perennial) leaves above. 
499. Since the sporophytes are large and long-lived 
their tissues are many and well-developed. Their 
tracheary tissue is almost wholly of the form known as 
tracheids, which are here marked on their radial faces 
‘with bordered pits. Proper fibrous tissue is scanty or 
wanting. The vascular bundles are of the open collateral 
type, arranged in a cylinder so that they provide for 
increasing the diameter of the stems and roots. Turpen- 
tine canals are present in all parts of the plant. 
500. There are nine families of conifers, a few only of 
which need be noticed here. In all the microspore cones 
are well developed, but there is a gradual simplification 
of the megaspore cones from those with many sporo- 
phylls tothose with fewor one. The Taxodiums (Family 
Taxodiaceae). Microsporophylls with two to eight spor- 
angia: megasporophylls woody, much en- 
ea larged distally, bearing two to several erect 
SS % or inverted seeds, forming compact, ellipsoid 
gc. ant cones; “seed scale’? wanting. Here are the 
Sequoia (seed- Bald Cypresses (Taxodium) and Redwoods 
(Sequoia), very old types that originated in 
the Mesozoic, and have persisted with reduced numbers 
to the present. The Redwoods, now confined to the 
mountains of California, were once widely distributed 
in the Northern Hemisphere. 
501. The Old Pines (Family Araucariaceae). Micro- 
sporophylls with five to fifteen spor- 
angia: megasporophylls woody, slightly 
enlarged distally, bearing one inverted % 
eed, forming compact spheroidal cones; Fic. 154.—Arauca- 
“seed scale’ rudimentary. The Old Sees hese 
Pines are now confined to the Southern Hemisphere, and 
