RHAMNUS INSULARIS ISLAND BUCKTHORN. 25 



176. RHAMNUS INSULARIS, GREENE. 

 ISLAND BUCKTHORN, ISLAND BEARWOOD. 



Ger., EUdndischer Kreuzdorn Fr., Nerprun insulaire ; Sp., 



Ramno de isla. 



SPECIFIC CHARACTERS : Lewes alternate, persistent, ovate-oblong, 1 to 1-J and 

 sometimes 3 in. in length, coriaceous, glabrous or sparingly pubescent, about 

 equally pointed at both ends, minutely glandular crenate-serrate with short stout 

 petioles and straight prominent mid-ribs, yellowish green, paler and frequently 

 yellowish beneath ; stipules falling away early ; new growths'sparingly pubescent. 

 Flowers four-numerous, dioecious, greenish, in small clusters from the axils of 

 the leaves on the shoots of the year, or of small bracts, with slender sparingly 

 pubescent pedicels rather more than -| in. in length ; calyx campanulate with 

 acuminate lobes : petals wanting (though according to Prof. Trelease are some- 

 times present) ; stamens with stout incurved filaments and large antlers ; pistil 

 with ovoid ovary and rather slender style two-lobed above. Fruit red, subglo- 

 bose, about in. or a trifle more in length, slightly grooved, with thin, dry flesh 

 and containing 1-3 ovoid nutlets pointed at the apex, dehiscent along the inner 

 angle, grooved on the back, with thin brown testa and thick foliaceous cotyledons. 



(Insularis is the Latin for belonging to an island and relates to the habitat of 

 the species.) 



A small tree with rigid branches, rarely more than 25 ft. (7 m.) in 

 height, with trunk sometimes 12 in. (0.30 in.) in diameter and having 

 a dark brown bark abont J in. thick and rough with small, firm, 

 irregular scales and ridges. 



HABITAT. The islands off the coast of southern California, Santa 

 Cruz Mountains on the adjacent mainland and Cedros Island off the 

 coast of Lower California, growing along slopes with Scrub Oak, 

 which it considerably resembles in general aspect, Ceanothus arboreus y 

 etc. 



PHYSICAL PROPERTIES. Wood very heavy, hard and close grained, 

 with very line regularly arranged ducts, susceptible of a very smooth 

 polish and of a rich red -brown color with scant yellow sap-wood. 



USES. We know of no use to which this small tree is applied, 

 though the bark might be used for dyeing purposes, as with other 

 representatives of the genus, and the wood would make excellent fuel. 



MEDICINAL PROPERTIES we believe have not been reported of this 

 species, but would doubtless be found to be tonic and laxative as with 

 other species of the genus. 



Rhamnus insularis, Greene, is considered by some botanists as a 

 variety of Rliamnus crocea, Nutt., (Rhamnus crocea insularis, 

 Sarg.\ but it is certainly a well-marked form differentiated from the 

 true R. crocea by characters as important as distinguish many other 

 species, and I am inclined to agree with Prof. Greene in giving it 

 specific rank. 



