88 RHAMNE^E. [RHAMNUS. 



430. AFFINITIES. "With Celastrinece, and certain Eupliorbiacece. PRO- 

 PERTIES. Purgative. Rhamnus yields a green dye. 



1. RHAM'NUS, L. BUCKTHORN. 



Leaves alternate, deciduous. Flowers in small axillary cymos, often 

 unisexual. Calyx-tube urceolate. Petals 4-5 or 0. Stamens 4 or 5, very 

 short. Disk coating the calyx-tube, honeyed. Ovary adnate below with 

 the calyx-tube, 3-4-celled ; style 3-4-fid, stigmas obtuse. Drupe girt with 

 the calyx-tube ; stones 2-4. Seeds obovoid, albumen fleshy ; cotyledons 

 flat or with recurved margins ; radicle short. Temp, and trop. regions, 

 none Australian ; species 60. ETYM. The Greek name, from the branched 

 habit. (Position of raphe variable, dorsal lateral or ventral.) 



1. R. cathar'ticus, L. branchlets spinous, leaves ovate acutely serrate, 

 nerves divergent, flowers 4-merous dioecious. 



Woods and thickets from Westmoreland southd., chiefly on chalk, perhaps 

 not wild N. of Durham ; rare in Ireland ; fl. May-July. A rigid shrub, 5-10 

 ft., much branched ; bark blackish. Leaves 1-2 in., fascicled at the ends of 

 the shoots, subopposite lower down, shortly petioled, young downy beneath ; 

 stipules subulate, deciduous. Flowers ^ in. diam., solitary or fascicled in the 

 axils of the fascicles of leaves on the previous year's wood, yellow-green, 

 proterandrous ; pedicel very short. Calyx of the male campanulate, female 

 cupular, lobes acute. Style 4- rarely 2- or 5-cleft. Drupe Jin. diam., globose, 

 black ; stones 4, obovoid, grooved at the back. Seed curved like a horse- 

 shoe; embryo obcordate, similarly curved. DISTRIB. Europe, N. Africa, 

 Siberia ; cult, for hedges in the U. States. 



2. R. Fran'gula, L. ; unarmed, leaves obovate quite entire, nerves 

 parallel, flowers 5-merous bisexual. Berry -bearing Alder. 



Woods and thickets, common in England ; Ayr and Moray in Scotland ; very 

 rare in Ireland ; fl. May-June. Shrub 5-10 ft. ; branches slender. Leaves 

 alternate, stipules subulate. Flowers ^ in. diam., few, axillary, greenish- 

 white, pedicels ^ in. Calyx campanulate. Style entire. Drupe ^ in. diam., 

 globose, black when ripe ; stones compressed, broadly obovoid. Seed of the 

 Fame form. DISTRIB. Europe, N. Africa, Siberia. Drupes cathartic, when * 

 unripe used to dye green. The Black Dogwood of gunpowder-makers. 



ORDER XXIY. SAPINDACEJE. 



Tribe ACERI'NE^:. 



Trees ; juice often sugary, sometimes milky. Leaves opposite, simple 

 or pinnate, deciduous. Flowers racemed or corymbose, often polygamous, 

 regular ; the lower or earlier in the raceme generally male, the terminal 

 2-sexual. Calyx 5- rarely 4-12-parted, deciduous, imbricate in bud. 

 Petals as many or 0, imbricate in bud. Stamens 8, rarely indefinite, 

 inserted on the annular, thick, lobed disk. Ovary laterally compressed, 



