This was not described until 1911, and not recognized in Ky. until B found it on "dry slopes in the Outer Bluegrass" during the 1930s. Uncertain records (mapped as open dots) include probable plantings and dubious records of "hortulana", which has not been reliably distinguished in Ky. The native range of munsoniana is reportedly similar to hortulana, largely in the lower midwest but shifted slightly to the south and east (Little 1977, K). P. munsoniana is also closely related to P. rivularis Scheele, a smaller shrubby plant of the southern Great Plains, and these two species have been combined by J. Rohrer in FNA9; however, there would still be much incompletely treated variation in this complex, especially in Texas (Correll & Johnston 1970; R.J. O'Kennnon, pers. comm.). The original range of munsoniana may have been centered in the Ozark region and perhaps parts of the Interior Low Plateaus, but it became widely grown in the late 19th Century, with several cultivars and hybrids (Hedrick 1911, Wight 1915). In the central Bluegrass, Short (1828-9) probably included it under "Prunus chicasa... Frequent in shrubberies, occasionally occurring wild"; but his flowering dates were a month later than now ("1st to 15th of May"). P. munsoniana is now largely restricted to old home sites, fencerows and thickets at the edge of old fields; but populations in HARD/HART and JESS appear native. It is likely that Native Americans used and dispersed this valuable fruit-producer. Cross-pollination is required for good crops. P. munsoniana often appears intermediate between angustifolia and hortulana in overall stature, flower size, fruit size and other characters, and may have hybrid origin (Shaw & Small 2004, 2005; F, GC, W, FNA 9). It tends to form taller trees than angustifolia (up to35 cm dbh and 8 m tall in FAYE), but it differs most clearly in its leaves, which are larger (mostly 5-11 x 1.5-5.5 cm versus 2-6 x 0.8-2 cm), less folded, more pubescent on the lower surface, with less prominent (small subapical) and less reddish glands, but usually with 1-5 glands on the petiole (versus 0-2). Also, it tends to have longer pedicels (ca. 8-12 mm versus 3-8 mm), sepals usually with marginal glands (versus absent), larger petals (ca. 4-9 mm long versus 3-6 mm) and fruit often relatively large with more oval versus globose shape (at least in Ky.); stones are generally ovoid (as in angustifolia) to subglobose (versus ovoid-ellipsoid in hortulana, americana, mexicana). However, there is much genetic variation in fruits, from relatively large sweet early-maturing ones in late Jun to those with less obvious quality for human consumption even at the end of their ripening in Aug-Sep. Some of the later maturing plants have relatively broad leaves and appear transitional to hortulana. Some seedlings from large sweet early fruit can grow into plants of the latter type (based on personal disappointment).