GROUP IV. PHANEROGAMIA : GVMNOSPERM^ : C0N1FER.E. 



487 



Sab-order II. Taxoide^ : the macrosporangiate flowers are, as a rule, not 

 cones ; the seed usually projects beyond the macrosporophylls (when present) 

 and has a succulent testa or an arillus : 

 flowers generally dioecious. 



Fam. 1. Podocarpece : the macrosporaugiate 

 flower consists of several macrosporophylls 

 each bearing a single macrosporangium : the 

 ripe seed is invested by an arillus : the micro- 

 sporophylls each bear two microsporangia : 

 the microspores have expansions of the 

 exine. 



This family includes the genera Saxegothea, 

 Microcachrys, Podocarpus, and Dacrydium. 

 Saxegothea resembles the Cupressineas n 

 that the macrosporophylls enclose the seeds : 

 this genus is monoecious. On the other hand 

 Dacrydium resembles the Taxeae in that the 

 macrosporophylls are very similar to the 

 foliage-leaves, and in that the macrospor- 

 angia are sometimes borne in the axils of 

 the macrosporophylls, and are then erect, 

 whereas in all other cases they are inverted. 



Fam. 2. Taxece : the macrosporophylls 

 are usually rudimentary or absent, and the 

 macrosporangia are borne on the axis : the 

 seed has an arillus in some forms, while in 



Fig. 307.— A Macrosporangiate 

 flower oi Junipenis Sabina, seen from 

 above : // fertile macrosporophylls, 

 bearing macrosporangia s; /'/' 

 upper part of sterile sporophylls 

 (mag.). JB and C Juniperus com- 

 munis. B young fruit: /// macro- 

 gporophylls, of which the anterior 

 is turned down : e the ovules. C ripe 

 fruit; the limits of the three carpels 

 are only distinguishable at the 

 apex. 



others it has a succulent testa : microsporo- 



phylls with 2-9 microsporangia : microspores without expansions of the exine. 



Phyllocladus, remarkable for its rudimentary leaves and for the development 

 of its dwarf-shoots into phylloclades, has thick persistent macrosporophylls ; 

 in the axil of each there is a single erect macrosporangium with an arillus : 

 flowers sometimes monoecious. 

 Ginkgo hiloha {Salisburia adianti- 

 folia), the Maiden-Hair Tree, is 

 characterised by its fan-shaped de- 

 ciduous leaves with furcate vena- 

 tion : the macrosporopliylls are 

 rudimentary : the macrosporangia 

 are borne in an opposite pair at the 

 end of a short stalk : no arillus, 

 but the testa of the seed becomes 

 succulent. Cepbalotaxus (the 

 Chinese Yew) and the genera Taxus 

 (the Yew) and Torreya (the Fetid 

 Yew of North America) have only 

 long shoots : the macrosporangiate 

 flowers and the ripe seeds of Ce- 

 pbalotaxus resemble those of Gink- 



PxG. 308.— .4 Branch of Taxus haccatn V)earing 

 a fruit/, which consists of a fleshy arillus en- 

 closing a seed. B Longitudinal section of the 

 end of a branch terminating in a macrospo* 

 rangiate flower; h scaly bracts; fc terminal 

 macrosporangium inucellus) ; i the integument; 

 m the micropyle ; a the rudiment of the arillus 

 (x20). 



