1923] REHDER, COLLECTION OF THE ARNOLD ARBORETUM 113 



P. pyramidalis meetensis Mathieu in Gartenfl. xxxvi. 674 (1887), pro synon. 

 P. Eugenei. 



? P. Charkoviensis Schroeder in Moeller's Deutsch. Gaert.-Zeit. xvm. 393, 

 fig. (1902). 



P. Canadensis X nigra B. Eugenei Ascherson & Graebner. Syn. Mitteleur. 

 Fl. iv. 45 (1908). 



This is supposed to be a hybrid between P. canadensis and P. nigra 



var. italica and originated in the nursery of Simon-Louis at Plantieres 



Metz in 1832. It approaches the Lombardy Poplar in its smaller 

 leave smore cuneate at the base and in the narrow pyramidal habit. It 

 is the Carolina Poplar of American gardens. 



To this group of hybrids (P. balsamiferaX nigra) apparently belong 



also P. Lloydii Henry and P. Henryana, P. Krauseana, and P. ramulosa 

 Dode. More information about the different forms mentioned above will 

 be found in Elwes & Henry, Trees Great Brit. & Irel. VII. 1814-1831. 



X Ribes Knightii (R. divaricatum X Lobbii), nom. nov. 



Ribes divaricatum X Lobbi J. K. Henry in Canad. Field-Nat. xxxiii. 94 (1920). 



Upright shrub; young branchlets puberulous, glabrous and yellowish 

 gray the second year; spines stout, simple or 3-parted, 0.8-1.5 cm. long, 

 light brown, lustrous. Leaves suborbicular in outline, deeply 3-lobed or 

 sometimes 5-lobed, 2-3.5 cm. across, with obtuse crenate-dentate or 

 lobulate lobes, dull green above and slightly pilose or nearly glabrous 

 at maturity, sparingly villose beneath, more densely so on the veins, 

 glandular when young; petioles 1-2.5 cm. long, thinly villose and slightly 

 stipitate-glandular, setose toward the base. Flowers with the leaves, 8-10 

 mm. long, 1-3 on a peduncle 4-8 mm. long; pedicels 2-4 mm. long, glabrous 

 or nearly so like the peduncle; calyx-tube campanulate, about 3 mm. 

 long, greenish outside and loosely villose like the sepals, the latter oblong, 

 dark red, more than twice as long as the calyx-tube, reflexed; ovary densely 

 stipitate-glandular; petals broadly cuneate-spatulate, 3 mm. long, white 

 or pinkish at the truncate apex, stamens about as long as sepals with oval, 

 green anthers. Fruit sparingly developed, subglobose, about 1 cm. across, 

 claret-red, glandular-setose, crowned by the persistent calyx. 



Specimens examined: Hort. George Fraser, Ucluelet, Vancouver, British 

 Columbia, G. Fraser, 1920 (flowers), July 27, 1922 (fruit). 



This handsome hybrid was found by Mr. George H. Knight of Mount 

 Tolmie Nursery, Victoria, British Columbia, growing among the parents, 

 R. divaricatum Dougl. and R. Lobbii Gray, at Mill Hill, Vancouver Island. 

 It was removed to his nursery and propagated and cuttings sent to Mr. 

 G. Fraser from whom we received our specimens. It was first described 

 by Professor J. K. Henry (1. c.) and its intermediate character clearly 

 set forth by him, though he expresses some slight doubt in regard to the 

 hybrid character of the plant, saying that in the genus spontaneous hybrids 

 between wild species are unknown in North America and that hybrids 

 are produced with difficulties by the horticulturist. His first statement 

 is apparently true and seems to apply not only to American but also Old 



