2828 



PRUNUS 



PRUNUS 



15. nigra, Ait. (P. boredlis, Poir. P. mollis, Ton. 

 P. americana var. nigra, Waugh). CANADA PLUM. 

 Lvs. mostly broader, the teeth glandular and remaining 

 on mature Ivs. as small callous points, but the teeth 

 otherwise nearly or quite blunt and thereby differing 

 from the sharply and deeply serrate Ivs. of P. americana; 



3219. Primus americana. The Weaver (X%). No. 14. 



petioles bearing 2 glands, near the top: fls. larger, on 

 slender dark red pedicels, white changing to pink, the 

 calyx-lobes glandular-serrate and glabrous on the 

 inside: fr. mostly somewhat oblong and orange-red, 

 the stone large and much compressed. New Bruns. to 

 Assiniboia, and in New England, N. Y., Mich., Wis., and 

 N. Ohio; possibly intro. in some of its southern ranges. 

 S.S. 4:149. A more showy tree than P. americana, 

 blooming earlier, and in its extreme forms appearing to 

 be very distinct. It has given rise to some of the best 

 fr.-bearing varieties, such as the Cheney, Itasca, 

 Oxford, Aitkin, Crimson, although not nearly so pro- 

 lific of cult, forms as P. americana. 



16. mexicana, Wats. (P. austrdlis, Muns. P. reticu- 

 Idta, P. tenuifolia, P. polydndra and P. arkansana, 

 Sarg.). BIG-TREE PLUM. The southern representative 

 of P. americana, as P. nigra is the northern : it is tree- 

 like, not sprouting from the roots or forming thickets : 

 Ivs. oblong-obovate to obovate, 3-5 in. long, rounded 

 or subcordate at base, abruptly acuminate at apex, 

 sharply and sometimes doubly serrate, short-pubescent 

 above at least when young and long-pubescent beneath 

 (and often confused with P. americana var. mollis); 

 petiole usually bearing 1 or more short-stalked glands 

 at or near the apex: fls. %in. across, white, in small 

 nearly sessile umbels, the pedicels usually glabrous; 

 calyx-lobes mostly reflexed, nearly or quite as long as 

 the tube, dentate at apex or sometimes entire, obscurely 

 glandular, pubescent within; petals variable in shape, 

 usually pubescent and mostly entire: fr. globose or 

 rarely oblong, sometimes 1 in. or more diam., pur- 

 plish red with bluish bloom; pit or stone obovoid or 

 nearly globular, turgid, the surface smooth or essentially 

 so. S. W. Ky. and W. Tenn. to Okla. and Mex. Wild 

 fr. is sometimes gathered, and it varies in size and 

 quality, but the species has received little attention 

 horticulturally, although used experimentally as a 

 stock to which its non-suckering habit adapts it. It is 

 said that a hybrid has been produced with P. salidna. 

 Wight, who has recently re-characterized this species, 

 writes that "Although long confused with Prunus 

 americana, and in the herbarium sometimes difficult to 

 distinguish from P. americana var. lanata, the species is 



nevertheless a very distinct one. It never forms thick- 

 ets, as does P. americana and its subspecies, but occurs 

 always as a tree with a well-defined trunk, which in the 

 older trees differs in its furrowed bark. The young 

 leaves as they appear are mostly somewhat obtuse at 

 the apex instead of acuminate; the older leaves are 

 usually broader in proportion to their length, and the 

 serration of the margin is slightly less pronounced. 

 The flowers also have petals somewhat broader in pro- 

 portion to their length than in P. americana, while the 

 stone is obovoid or round and more turgid." 



17. hortulana, Bailey (P. hortulana var. Wdylandii, 

 Bailey). HORTULANA PLUM. Fig. 3220. Tree distinct, 

 not sprouting from the root or forming thickets or 

 hedges, 15-30 ft. tall, with thinnish 

 exfoliating bark and brownish twigs: 

 Ivs. oblong-obovate or elliptic-ovate, 

 the blade 3-4 in. long, rather broad to 

 rounded at the mostly oblique base, 

 long-acuminate, yellowish green, gla- 

 brous above and more or less shining, 

 \ lightly pubescent or practically gla- 

 . brous beneath, the margins shallowly 

 and obtusely serrate or crenate-serrate ; 

 petiole usually bearing 1 or 2 or more 

 small glands toward the apex: fls. pre- 

 ceding the Ivs., white, small (about 

 ^in. broad), the pedicels slender and 

 glabrous; calyx-lobes about as long as 

 the tube, oblong-ovate, glandular on 

 margin but otherwise glabrous or 

 nearly so on exterior, mostly obtuse; 

 petals oval to nearly orbicular, clawed: 

 fr. globose or short-oblong, %-l in. diam. in the wild, 

 red to yellow and mostly white-dotted, with little or 

 no bloom, not thick-skinned; pit or stone various, glo- 

 bose to oval or oblong, the surface more or less reticu- 

 lated. Cent. Ky., Tenn., to Iowa and Okla. This 

 species has yielded a good number of cult, varieties, as 

 Kanawha, Golden Beauty, Cumberland, Leptune, Way- 

 land, Moreman, Sucker State. The species was first 

 distinguished in 1892 to desig- 

 nate varieties of plums inter- 

 mediate between P. americana 

 and P. angustifolia (the two 

 species at that time clearly 

 separated); these intermediate 

 varieties were then said to 

 "represent at least two other 

 species, and perhaps even 

 more" (G.F. 5:90), one of 

 which it was proposed to sepa- 

 rate as P. hortulana. Later stu- 

 dents have separated P. Mun- 

 soniana from these varieties, 

 and have redefined other 

 species. Subsequently it was 

 supposed that P. hortulana 

 represents a range of hybrids 

 between P. americana and P. 

 angustifolia, and it is not yet 

 known what part hybridization 

 has played in the origin of these 

 forms, although the evidence 

 accumulates that separate 

 specific types are involved. 



Var. Miner!, Bailey, is nearer 

 to P. americana, and represents 

 the northward extension of 

 the group; it is known by 

 its thicker and duller Ivs. 

 which are very veiny below 

 and coarsely toothed and 



somewhat obovate in out- 3220. Prunus hortulana (XK). 

 line, and by a late firm fr. NO. 17. 



