32 HOUGH'S AMERICAN WOODS. 



tribution and becomes very abundant on the slopes of the Alleghanies, 

 where it is scattered extensively as an undergrowth in the forests, 

 or in places forms almost impenetrable and exclusive thickets. 



PHYSICAL PROPERTIES. The wood is rather heavy, hard, com- 

 pact, of very fine grain, with many very small open ducts and fine 

 medullary rays. It is of a pale brown color with abundant lighter 

 sap-wood. Specific Gravity, 0.6303 ; Percentage of Ash, 0.36 ; Rela- 

 tive Approximate Fuel Value, 0.6280; Coefficient of Elasticity, 

 64578; Modulus of Rupture, 663; Resistance to Longitudinal Pres- 

 sure, 439 ; Resistance to Indentation, 191 ; Weight of a Cubic Foot in 

 Pounds, 39.28. 



USES. Little use is made of the wood of the Rhododendron, 

 excepting occasionally in turnery for tool-handles and as a substitute 

 for box-wood in engraving. The great point of usefulness in the 

 species is its value for ornamental planting, for which it is probably 

 the most popular of American shrubs. 



MEDICINAL PROPERTIES. The bark is sometimes uses as a 

 remedy for rheumatism and gout. 



ORDER SYMPLOCACE^: SWEET-LEAF FAMILY. 



Leaves simple, alternate, without stipules; buds scaly. Flowers regular, mostly 

 perfect and yellow, in axillary or lateral clusters; calyx 5-lobed, campahulate, the 

 tube adnate to the ovary; corolla deeply 5-lobed, with imbricated lobes; disk 

 none ; stamens numerous, more or less united at . base into clusters, with long 

 filiform filaments and small 2-celled anthers opening laterally; ovary 2-5-celled 

 with simple style, terminal stigma and usually 2 anatropous ovules suspended in 

 each cell. Fruit usually a dry drupe crowned with the persistent calyx-lobes, thin 

 flesh and one bony stone; embryo straight in fleshy albumen. 



A family of the following single genus of trees and shrubs. 



GEXUS SYMPLOCOS, L'HER. 



For characters see description of the family, this being the only genus. 



The genus ttymplocos comprises about 180 species, so far as known, chiefly of 

 the tropical regions of America, Asia, and Australia. One inhabits southeastern 

 United States ranging as far north as southern Delaware. The name is from 

 Greek roots referring to the fact that the stamens are united together in clusters 



285. SYMLOCOS TINCTORIA, L'HER. 



SWEET-LEAF. HORSE-SUGAR. 

 Ger., Zuckerblatt Fr., Feuille sucree; Sp., Hoja dulca. 



SPECIFIC CHARACTERS: Lea ves oblong to obovate, mostly 4-6 in. long, cuneate 

 at base, acute or acuminate, obscurely crenate, serrate or subentire, revolute in the 

 bud, tomentose beneath at first but at maturity lustrous dark green above paler 

 and pubescent beneath, subcoriaceous and with arcuate veins; petioles short stout 



