rws 



XArrRAL HISTORY OF FLANTS. 



i^ lu'rmaplirodite ; on the edges of the concave receptacle are borne 

 five uneciual quincuncinllv imbricated sepals, and as many alternating 

 petals, also imbricated. Tliere are a score of perigynous stamens in- 

 serted towards the edge of the glandular disk lining the receptacular 

 cup, each composed of a free filament and an introrse two-celled anther, 

 dehiscing longitudinally. The gyna^ceum consists of an ovary of 

 five alternipetalous cells,' each surmounted by a style with an irre- 

 gularly dilated and stigmatiferous apex ; and in the ventral angle 

 of each are two collateral descending anatropous ovules, whose 

 micropyles look upwards and outwards.- An elongated obturator, 

 formed by a prominence of the placenta, projects above each micro- 

 pyle. The fruit is woody and loculicidal, separating into five thick 

 valves when ripe. The seeds are compressed and winged, containing 

 a fleshy, exalbuminous embryo, with its radicle superior. Z. mes- 

 pi I aides is a small Mexican tree, with simple, alternate leaves, and 

 little lateral caducous stipules. The flowers are solitary, terminal, 

 ur they more rarely form a few-flowered terminal cyme. On the 

 peduncle of each flower are two bracts. 



With the habit and foliage of Spiraa, to which it was formerly 

 joined, Exochordcc" (fig. 456) possesses flowers exactly 

 like those of Lindleya,^ i.e., a concave receptacle, lined 

 b}^ a glandular disk, bearing on its edges five quin- 

 cuncial sepals, as many imbricated petals, and fifteen 

 or twenty stamens of the Rosacea f also an ovary of 

 five cells, surmounted by an equal number of styles 

 dilated and stigmatiferous at their apices, and con- 

 taining in the ventral ane^le of each cell two descending 

 ovules, whose micropyles look upwards and outwards, 

 and are capped by a cellular obturator. The fruit alone 

 is markedly difterent. The perianth and receptacle 

 come off it altogether, leaving it quite bare as a capsule 

 with five thick obtuse wings, gradually tapering towards the base 

 and rounded on the back, all united round the central axis from 

 which they radiate, their intervals forming deep dihedral angles. 



Exochorda 

 grandiflora. 



Fig. '156. 

 Fruit. 



' Tliose cells are usually incomplete, so that 

 the placentas really become parietal. 



" With two coats. 



^ LiNni... Garrlfi,,. CArow. (1858),925.— R.H., 

 Oen., m2, n. 21. 



* They are sometimes tetra- or hexamerous. 



■^ There ai-e nearly always three in front of each 

 petal, the median one beinsj smallest, and in- 

 serted below the other two. It is those in front of 

 the sepals which may sometimes be quite absent. 



