88 EEAMNEjE. [Rhamnus. 



430. — Affinities. "With Celastrinece, and certain Euphorbiacece. — Pro- 

 perties. Purgative. Rhamnus yields a green dye. 



1. RHAM'NUS, L. Buckthorn. 



Leaves alternate, deciduous. Flowers in small axillary cymes, 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 ; pedicels very short. Calyx of the male campanulate, female 

 cupular, lobes acute. Style 4- rarely 2- or 5-cleft. Drupe J in. 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 XXIV. SAPINDA CEiE. 



Tribe Aceri'nejb. 



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, 



