I 



NATIVE AMEKICAN SPECIES OF PEUNUS. 47 



represent its parentage. Nevertheless, the close resemblance to P. 

 angusiifolia in some of the flower characters, particularly the calpc 

 lobes, which are entirely without glands, suggests either that species 

 or P. angustifoUa vmians as one of the parents. A hybrid of the Wild 

 Goose and P. cera^ifera might also be expected to produce a form 

 with larger and longer leaves than the Marianna. 



Pruxus Orthosepala Koehne. 

 Pruaus orthosepala Koehne, 1893, Deut. Dendrol., p. 311. 



Leaves (PI. lY, fig. 3) varying from oblong-lanceolate to obovate- 

 lanceolate, mostly 4 to 6 cm. long, 1 to 2.5 cm. broad, narrowed at 

 the base and acute or acuminate at the apex, the marguis serrate 

 with acute or more often slightly obtuse teeth, these occasionally 

 tipped with a caUous point, bright green, glabrous, and somewhat 

 lustrous on the upper surface, pale green and glabrous or with a few 

 scattered hairs along the rather prominent midvein; petioles 8 to 15 

 mm. long, puberulous along the upper surface and eglandular or with 

 one or two glands near the upper end. Flowers appearing the last 

 of April or early in May, 10 to 14 mm. broad in 3 to 4 flowered umbels; 

 pedicels 3 to 5 mm. long, glabrous; calyx tube campanulate, 2 to 2.5 

 mm. long, glabrous, the oblong obtuse lobes about 2 mm. long, 

 glabrous or nearly so on the outer surface, ciliate on the margin and 

 sparingly pubescent within, dentate or entire at the apex; petals 

 oblong-obovate, 4 to 5 mm. long, 2.5 to 3 mm. broad, entire or erose 

 at the aj^ex, white, or in age with a distinct pinkish tinge. Fruit 

 ripening at the Arnold Arboretum about the middle of September, 

 globose, about 2.5 cm. in diameter, red with white dots, and covered 

 \vith bloom; stone oval (PL XIII, fig. 1), about 15 mm. long, 12 mm. 

 broad, slightly pointed at the base and romided at the apex, rather 

 irregularly grooved near the ventral suture, grooved along the dorsal 

 edge, and the surface obscurely i-ugose. 



Prunus orthosepala, as it grows in the few American arboreta where 

 it is cultivated, is a much-branched, spreading shnib about 5 feet high. 

 The bark of the stem and larger branches separates in platelike scales; 

 that of the smaller branches is dark brown in color, marked with 

 lighter colored lenticels, whih^ that of tl^o young branchlets is chestnut 

 colored. 



The history of this species, as given by Sargent (67), is as follows: 



In .June, 1880, Dr. George Engelmann, of St. Louis, sent to the Arnold Arboretum 

 a package of seeds marked "Prunus sp., southern Texas." Plants were raised from 

 the.se .weds, and in 1888, or earlier, they flowered and produced fruit which showed 

 that they belonged to a distinct and probably undescribed species. A name, how- 

 ever, was not proposed for it, and, in 1888 probably, plants or seeds were sent to Herr 

 8p&th, 01 tho Pvixdorf Nurseries, near Berlin, wlien^ this plum was found in flower by 

 Or. Emil Koehne, who has dew;ribed it under the name of F'rumu) orihonepalo. 



