132 RHAMNUS-RHUS. 



luteo''ta, (dier's weed, }'.) leaves lanceolate, undulate, enure, each side of the 

 base toothed; calyx 4-cleft; flowers in a spike. Introduced. 



RHAMNUS. 5—1. (Rhamni.) [From raio, to destroy, on account of the many thorns of 

 some of Us species.] 

 alnifo'lias, (dwarf-alder, w-g. M. T^.) unarmed; leaves oval, acuminate, ser 

 rulate, pubescent on the nerves beneath; flowers dioecious; peduncles 1 

 flowered, aggregate; calyx acute; fruit turbinate ; berries black. Rocky 

 hills. 

 cathar"licus, (buckthorn, y-g. T2.) branches spiny ; leaves opposite, ovate ; 

 flowers 4-cleft, dioecious. Mountain woods. 



KHEUM. 9—3. (Polygonal.') [From Hha, an ancient name of the WoJga, on whose banks i; 

 was discovered.] 



falma'ta, (rhubarb, J. %.) leaves palmate, acuminate. Ex. 



rhapon"ticum, (pie rhubarb, w. J. %.) leaves heart-ovate, obtuse and acute, 



smooth ; veins sub-pilose beneath, the sinuses at the base dilated ; petioles 



furrowed on the upper side, rounded at the edge ; radical leaves very large. 



2-4 f. Ex. 

 RHEXIA.. 8—1. dMelastomicB.) 

 7nariana, (w-r. Ju. %.) very hairy, leaves lanceolate, acute at each end, 3- 



nerved, sub-petiolate ; calyx tubular, nearly smooth. Var. purpurea, has 



purple flowers; petals obovate, hairy on the outer surface. 

 virgin"ica, (deer-grass, meadow-beauty, p. Ju. %.) stem with winged angles, 



square, somewhat hairy ; leaves sessile, ovate-lanceolate, ciliale, serrate, 3- 



7-nerved, sprinkled with hairs on both sides; corymbs dichotomous. Wet 



meadows. 1 f. 

 RHINANTHUS. 13—2. (Pediculares.) [From rin, nose, and anthos, flower.] 



cristagal"ii, (yellow-rattle, y. J. ©.) upper lip of the corolla arched ; calyx 



smooth; leaves lanceolate, serrate, opposite; flowers axillary, somewhat 



spiked, yellow. Meadows. 



RHIZOPHORA. 12—5. (Saliearia.) [From ?A;20, root, and p^ero, to bear, on account of its 

 peculiar root.] 



7?ie7i"^Ze, (mangrove, T^.) leaves acute, ovate, opposite; peduncles axillary; 

 fruit clavate, subulate. 



RHODODENDRON. 10—1. (Rhododendra.) [From radon, a rose, dendron, tree ; so called 

 because it resembles the rose.] 



max"imum, (wild rosebay, E. r. Ju. T^.) leaves oblong, glabrous, paler be- 

 neath ; umbels terminal, dense ; corollas sornewhat bell-form. 4-20 f. 



fon"ticum., (rosebay, p. b.) leaves oblong, glabrous, both sides coloured alike ; 

 corymbs terminal ; corolla bell-wheel-form ; petals lanceolate. Ex. 



lappon'icum, (p. Jn. l^.) flowers in terminal, leafy clusters, campanulate; sta- 

 mens mostly 8 ; leaves elliptical, punctured, coriaceous, evergreen ; shrub 

 8-10 i. White hills. 



RHODORA. 10—1. (Rhododendra.) 



canadcn'sis, (false honeysuckle, p. M. Tj.) leaves alternate, oval, entire, pu- 

 bescent-glaucous beneath ; flowers in terminal umbels or clusters, appear- 

 ing before the leaves. Mountain bogs. 2 f. 



RHUS. 5—3. (Terebintacea.) [From Tea, to flow, so called because it was supposed to be 

 useful in stopping haemorrhages.] 



gla'brmn, (sleek-sumach, g. r. Ju. I7.) branches, petioles, and leaves glabrous ; 

 leaves pinnate, many-paired ; leafets lance-oblong, serrate, whitish beneath ; 

 fruit silky. The leaves are used for tanning morocco leather. Berries 

 red and sour. 6-12 f. 



ver'nix, (poison-sumach, y-g. J-Ju. 1^.) very smooth; leaves pinnate; leafets 

 in many pairs, oval, abruptly acuminate, entire ; panicles loose ; flowers di- 

 oecious. A small tree. 



toxicode n" dron., (g-y. J-Ju. Tj.) stem erect; leaves ternate; leafets broad^ 

 oval, entire or sinuate, dentate, sub-pubescent beneath ; flowers dioecious, 

 in sessile, axillary racemes. 1-3 f. Var. radicans, (poison ivy,) stem 

 climbing. 



'yphi'na, (stng's-horn sumach, y-g. J. h^.) branches and petioles very villose; 



