490 



BOTANY 



cones consisting of numerous sporophylls attached to a short erect axis. Each 

 sporophyll bears two microsporangia on the lower surface ; the microspores are 

 provided with distended wings. 



Taxus baccata is the only European representative of the family. The Yew, 

 which is now for the most part artificially introduced, had formerly a wide distribu- 

 tion as an evergreen undergrowth in our native woods (Figs. 456, 457). Isolated 

 examples of large size occur in North and Central Germany, and it occurs as a 



Flo. 4a6. Taunts baccata. A, branch with feinalf dowers: '. two ovules mi the- s.-nnc shoot (nat. 

 size); B, leaf with axillary, fertile shoot (x 2); f, median longitudinal section of a primaiy 

 and secondary shoot; r, vegetative cone of the primary shoot ; a,' rudiment of the aril; e, 

 nidiment of the embryo-sac ; n, nucellus ; i, integument; HI, micropyle (x 48). Fo/soxoi-s. 



more important constituent of the vegetation in Switzerland, e.g. on the steep 

 slopes at Uetli. The Yew tree attains a height of 10 m. All the branches are 

 shoots of unlimited growth. The leaves stand on all sides of the ascending main 

 shoots but in two rows on the horizontally expanded lateral branches. They are 

 narrow, flat leaves and persist for several years. The tree is dioecious ; the flowers 

 are situated on the lower surface of the twigs and arise in the axils of the leaves 

 of the preceding year. The male flowers are invested at the base by a number 

 of scale leaves and contain some 10 peltate stamens, each of which bears 5-9 

 pollen-sacs. The mode of opening of the sporangia is peculiar. The outer wall 



