Nov. 10,1913 
Pubescent-Fruited Species of Prunus 
153 
the Texas and Mexican wild almonds in the subgenus Emplectocladus of 
Prunus. This has been done with a full realization that most definitions 
of this genus describe the flowers as perfect, though Sargent 1 and Schnei¬ 
der extend the definition to include polygamo-dioecious flowers. No 
reference to dioecious or polygamo-dioecious characters in any Asiatic 
forms of Prunus has been found. 
While a more complete knowledge of the Asiatic forms 2 may disclose 
closer affinities for these three species, they are retained provisionally as 
the sole member of the subgenus Emplectocladus. With our present 
knowledge of these forms the seven species of Prunus studied in this 
paper should be grouped as follows: 
SCHEME OF CLASSIFICATION 
PRUNUS 
Subgenus Emplectocladus 
Low divaricate or erect shrubs with more or less spinescent branches. Bark on new 
growth gray or brownish, glabrous or more or less pubescent. Leaves conduplicate in 
vernation; borne singly on vigorous young growth or apparently fascicled on budlike 
suppressed branchlet, with or without stomates in upper epidermis. 
Flowers solitary or gemminate, sometimes crowded on short fruiting spurs, subsessile, 
precocious or coetaneous with the leaves, dioecious by the abortion of stamens or 
pistils; calyx cup obconic or campanulate, glabrous or faintly puberulous on the 
outer surface, minutely hairy within; stamens usually. 10 to 15 on short filaments, in 
three more or less well-defined circles, inserted on the margin of the cup and on the 
walls below; ovary and base of style pubescent. 
Fruit seldom more than 1 cm. long, pubescent, subglobose or irregularly ovate, with 
thin, dry flesh splitting tardily, and smooth or obscurely ridged stone. 
Four species: Prunus fasciculate Gray, Prunus minutiflora Engelm., Prunus micro - 
phylla Hems., and Prunus havardii (Wight), n. comb. 
Subgenus Euprunus 
SECTION PILOPRUNUS, N. SECT. 
Low, much branched, often procumbent, scarcely spinescent shrubs, with gray 
or brown, pubescent young wood. 
Leaves conduplicate, without stomates in upper epidermis, tomentose, glandular 
serrate. 
1 Sargent, C. S. Silva of North America. Boston, 1892, v. 4, p. 7. 
2 Prunus pedunculata (Pall.) Maxim, and P. pilosa (Turcz.) Maxim, of Mongolia are said by Koehne (PI. 
Wilsonianae, pt. 2, p. 273) to have the calyx cup dry within and minutely hairy at the insertion of the 
s tamens. Schneider figures (Laubhk., v. 1, p. 598, fig. 335 <*) the whole interior of the calyx cup of P. pedun¬ 
culata as finely hairy. Tittle is known as to the flower characters of Prunus boissierii Carr, from Asia Minor 
referred to P . pedunculata by Schneider, but which differs in having sessile flowers. These plants are 
referred to the section Emplectocladus by Schneider, but his figures of P. pedunculata show a perfect flower 
and no hint is given in descriptions of the other forms of their flowers being dioecious. These species, as 
well as the little-known P. mongolica and P. dekiscens Koch., grouped along with them by Koehne (PI. 
Wilsonianae, pt. 2, p. 274), and P. petunnikowi Utw. doubtfully referred to this group by Schneider(Uaubhk 
v. 2, p. 974), all need to be studied carefully so as to permit of a careful comparison with the American forms 
here referred to the section Emplectocladus. 
13000°—13—s 
