432 



DICOTYLEDONES. 



457. 



Hura crepitans (Sand-box tree) has a many-carpellate gynceceum, 

 which separates with great violence when ripe. A drupe is found 

 in Hippomane mancinella (the Mancinil-tree, W. Ind.). Alchornea 

 (Coelebngyne) ilicifolia is well known on accoiint of its "partheno- 

 genesis "; only the ? -plant has been introduced into Europe, but it 

 nevertheless produces seeds capable of germination; these have 

 generally several embryos. 



Euphorbia (Spurge) has the most reduced flowers, which are 

 -A. borne in a very complicated 



^v \ 



^$M& inflorescence. Each ^-flower 



(Fig. 460 B) is naked, and con- 

 sists of one stamen only (ter- 

 minal on the axis). In the 

 closely allied genus Anthostema, 

 a small perianth is situated at 

 the place where, in Euphorbia, 

 there is a joint in the "fila- 

 ment," Fig. 461 A). The ?- 

 flowers (Fig. 460) are naked, 

 with a 3-locular ovary and 3 

 bifid styles. (Anthostema has a 

 distinct perianth (Fig. 461 B) ; 

 in a few Euphorbias traces of a 

 perianth are present). In Eu- 

 phorbia the c- and ? -flowers 

 are grouped into flower-like in- 

 florescences termed " cyathia." 

 Each cyathium consists of a 

 centrally placed ? -flower which 

 is first developed, surrounded 

 by 5 groups of ^-flowers (sta- 

 mens) placed in a zig-zag, with 

 a centrifugal order of develop- 

 ment (Figs. 459, 460 B\ that 

 is, in unipared scorpioid cymes; 

 these flowers are surrounded by 

 an involucre of 5 leaves united 

 into a bell-shaped stricture (Fig. 459, 1-5) (resembling a calyx) ; 

 on its edge are placed 4, generally crescent-like, yellow glands, 

 one in each of the intervals, except one, between the lobes of the 

 involucre (shaded in Fig. 459; see also Fig. 460 A}. Scale-like 



458. 

 -Plnjllanthus (Xylopltylla] 



456. 



FIGS. 45C-458. 

 angusiifolius. 



FIG. 456. Leaf-like branch with flowers 

 (nat. size). FIG. -157. c? -flower ; and 

 FIG. 458, ? -flower (mag). 



