230 



TAX ACE. E 



[GVMNOGENS. 



Order LXXV. TAXACE.E.— Taxads. 



Taxincac, Rich. Conif. 124. (1826) ; Bartl. Ord. A'at. 95. (1830) ; Martius Conspectus, No. 58. (1835; ; 



Diagnosis. — Gymnogens with repeatedly branched continuous stems, simple leaves often 

 fork-veined, solitary females, 2-celled anthers opening longitudinally, and the mem- 

 brane next the nucleus inclosed. 



Fig. CLX. 



Fig. CLIX. 

 Trees or shrubs with continuous, unarticulated branches. Wood having the ligneous 

 tissue marked with circular disks. Leaves usually narrow, rigid, entire and veinless, 



evergreen, alternate or distichous ; sometimes dilated 

 and lobed, and in those cases having forked veins of 

 equal thickness. Flowers $ <j? j naked, but surrounded 

 by imbricated bracts. $ Stamens several ; filaments 

 usually monadelphous ; anthers combined or distinct, 

 opening longitudinally. $ solitary. Ovules naked, 

 the foramen at their apex, their outer skin becoming 

 finally hard. Seed usually supported or surrounded 

 by a succulent imperfect cup-shaped pericarp. Albu- 

 men fleshy. Embryo straight, dicotyledonous, either 

 antitropal or orthotropal. 



Yews are separated from Conifers by their fruits 

 not being collected hi cones, each ovule growing singly, 

 unprotected by hardened scales ; so that this is a degree of organization yet lower than 

 that of Conifers themselves. It is also to be observed, that in this Order the leaves do not 

 always preserve the veinless needle-shaped state of Conifers, but expand and form veins, 

 which are then forked and of uniform thickness, just as in Ferns. To me it appeal's 

 that this deviation on the part of many genera from the Coniferous form of fruit, is a 

 good practical distinction. Mr. Bennett, however, is of opinion that Taxads should 

 not form a distinct Natural Order, but ought to be associated with Conifers ; at least such 

 I presume to be the bearing of his observations in Horsfield's Plantw Javanica, p. 37. 

 In the opinion of this excellent botanist, Taxus belongs to Cupressese, while Podocarpus 

 and Dacrydium should be associated with Abietese, an opinion to which he seems to 

 be led, in part at least, by considerations connected with the pollen of those plants. 

 What these peculiarities of the pollen are, is explained at p. 228. But I see no reason 

 why two kinds of pollen should not be comprehended under the Order of Taxads as 

 well as under Conifers ; and the importance of distinctions in the pollen of plants appears 

 to me to be at least very doubtful. 



Fig. CLIX. — Taxus haccata loaded with male flowers; 1. a male flower; 2. an anther; 3. a female 

 flower; 4. a vertical section of an ovule ; 5. of a ripe fruit ; 6. of a ripe seed, showing the emhryo.— 

 N.B, 4. and (i. are the same part in youth and age ; 5. is the ripe ovule, with an accessory cup 



Fig. CLX. — Perpendicular section of the ripe fruit of Taxus, together with Hie cup-shaped pericarp, 

 which rises round it after the pollen has taken effect upon the ovule. 



