148 Mearns New Species of Poisonous Sumachs. 



Museum. To others I am indebted for much additional material 

 from private herbaria; also to Mr. Gerrit S. Miller, Jr., and 

 Mr. Charles Louis Pollard, for special assistance. In the Na 

 tional Herbarium is another entire-leaved form, from Florida, 

 related to the Rhode Island species. 



Prof. Amos Eaton, in the 4th edition of his Manual,* de 

 scribes the "poison vine" or "poison ash" under the specific name 

 toxicodendron, and gives the following: "Var. radicans, (poison 

 ivy) stem climbing and rooting: leaflets broad, entire, or with 

 scattered teeth. Var. quercifolium, (poison oak) erect, low: 

 leaflets variously sinuate-lobed. Var. microcarpon, leaflets ob 

 long-oval, long-acuminate, sub-rhombic: fruit very small." 

 Neither these names and descriptions nor those of later writers, 

 Toxicodendron vulgare Miller included, are applicable to the 

 entire-leaved littoral forms occurring on Rhode Island and in 

 Florida, which are described below. 



Rhus littoralis sp. nov. 



RHODE ISLAND SUMACH. 



Type. From Newport, Rhode Island. No. 403,300 U. S. National Her 

 barium. Specimen consisting of three parts: (1) a botanical sheet with 

 branch, leaves, and fruits (September 10, 1901); (2) a quantity of drupes; 

 (3) central stem (all from the same plant), 2 meters in height, cut in 

 lengths of a little less than 4 decimeters each (November 28, 1901). 

 Collected by the author. Original number, 233. 



Description. An erect, woody shrub, 2 to 4 meters in height, with 

 stem 1 to 2 dm. in circumference. Wood fine-grained and white. Stem 

 terete, with scattered aerial rootlets near the ground ; branches longi 

 tudinally ridged; bark gray or reddish brown on new growth; young 

 shoots and buds covered with a brown pubescence. Leaves thick, 

 petioled, 3-foliate, resinous spotted, and with brownish pubescence on 

 veins; petiole of leaf 50 to 200 mm., of lateral leaflets I to 10 mm., and 

 of the terminal leaflets 10 to 30 mm.; leaflets oblong-lanceolate, inequi 

 lateral, rounded at base, and acute at apex, with margin entire, 50 to 

 100 mm. in length by 20 to 60 mm. in breadth. Flowers green, in loose 

 axillary panicles. Fruit a globose drupe, consisting of a flattened, striated, 

 1 -celled stone; a persistent, white, lobed pericarp; with a greenish or 

 yellowish fugacious outer investment which at first is very pubescent and 

 afterwards smoothish. In plate III are shown the dessicated pericarps 

 of four species as they appear in winter after the epicarp has separated 



*A Manual of Botany for the Northern and Middle States of America, 

 etc., Albany, 1824, p. 428. 



