CONSPECTUS OF THE ORDERS. XVU 



the ovules (usually more thau 2) iu slightly hollowed-out notches ou each side ot 

 the stalk up to uud includiug the base of the ])lade [(Tyca.s] or more often uuyuiculate- 

 peltate with ouly 1 ovule from near each of the iuner angles of the baae of the head. 

 Ovules (macrosporangia) orthotropous, sessile or subsessile, obliquely erect [C't/cc«.s] 

 or reversed and parallel to the claw, directed towards the axis of the cone ; 

 integument 1, stout, perforated at the apex by the micropyle ; uucellus free upwarils 

 from the integument, produced into a beak and passing iuto the micropyle, its apical 

 tissues breaking down and forming a pollen-chamber in the mucilaginous liquid of 

 which fertilization takes place. Mature cones little changed except for the harder 

 texture of the more or less spreading scales. Seeds large, globose to oblong, drupe- 

 like ; testa of a fleshy, variously coloured outer coat and a hard inner layer, inside 

 which there is a membrane containing the vascular system of the ovule and formed 

 of the innermost strata of the integument together with portions of the uucellus. 

 Endosperm fleshy. Embryo 1, axile, subcylindrical, borne ou a filiform, spirally 

 coiled up suspensor ; cotyledons 2, rarely 1 (by suppression) or 3-6 ; radicle superior, 

 surrounded by a cap-like coleorrhiza. Woody plants with a stunted, tuber-shaped 

 stem or a columnar trunk of varying height, usually simple, rarely forked and always 

 densely covered upwards with the scars or persistent bases of the cataphylls. Leave« 

 mostly of 2 kinds, namely scale-like cataphylls acting as bud-scales and exstipulate 

 fronds, both produced in alternating series ; the cataphylls ovate to subulate, mostly 

 woolly ; the fronds gathered in dense terminal crowns, pinnatisect or pinnate, rarely 

 2-piunate, often very long, coriaceous, usually disarticulating at the base ; rhachis 

 generally straight, rarely involute in vernation ; pinnae straight or involute. 

 Strobiles subsessile or borne on ebracteate or bracteate peduncles, solitary or in 

 clusters below and often close fo the apex of the stem or [_Cycas'] the female cones 

 truly apical, their axis continuing growth after maturation and producing a series 

 of cataphylls, followed by one of fronds, a process which may be repeated many times 

 at varying intervals during the life of the plant. 



CXXX. CifCADACE2E. Only Order. 



