Nov. io, 1913 
Pubescent-Fruited Species of Primus 
175 
of the University of California, and material collected by Mr. Purpus for 
the writer: 
Prunus microphylla Hemsley. (Fig. 8.) 
Amygdalus microphylla , H., B., and EL, Nov. Gen. et Sp. PI., v. 6, p. 243, pi. 564, 1823. 1 
Prunus microphylla (H., B., and K.) Hemsley, Biol. Centr. Amer. Bot. v. i, p. 118, 1879. 
Ulus., Schneider, C. K., Laubhk., Lfg. 5. P* 598, fig. 335, q, r, s, t; H., B., and K., loc. cit. 
A low branching shrub with slender twigs destitute of thorns; puberulous on new 
growth, sometimes also on wood of second year, bark greenish or reddish brown, 
turning to silvery or dark gray on older wood. Leaves narrowly elliptical or on 
fresh shoots broadly lanceolate; base slightly produced or cuneate; margin crenately 
serrate with blunt glandular or callus tipped teeth; dull green, faintly puberulous 
above; grayish green with scattered short hairs on the lower surface; nearly glabrous 
on old growth; 1.5 to 2 or 3 cm. long; petiole short, puberulous; stipules 2 to 3 mm. 
long; slender attenuate, russety, hairy with glandular teeth; stomatesnot present in 
upper surface of the blade. 
The flowers, appearing in April or May before or with the leaves, are solitary, 
minute, and dioecious by the abortion of the stamens or pistils. 
Staminate flowers sessile, with glabrous campanulate calyx tube 2 to 3 mm. long; 
lobes short, triangular, with expanded base and glandular ciliate margins; tube 
minutely hairy within; petals white, broadly obovate, entire or with notched or erose 
margins. Claw short or wanting. Stamens on filaments 1 to 2 mm. long are 10 to 15 
or 18 in two or three circles, one circle opposite the petals, one opposite the calyx 
lobes near the throat, and a more or less complete circle below these. (One flower 
had 15 stamens and the three circles complete.) The pistil is minute, glabrous, and 
abortive. 
In the pistillate form the stamens, with very short filaments, are abortive; the pistil, 
4 to 5 mm. long, has the ovary and lower portion of the style pubescent; stigma 
expanded. 
The mature fruit is 1 to 1.5 cm. long, oval with about equally rounded ends, apiculate 
by persistence of the style, but little compressed, densely rusty pubescent; sarcocarp 
1 Their description is translated as follows: 
Amygdalus microphylla. Tab. DLXIV. 
Amygdalus oblong, acute, mucronate, crenate-serrulate with glabrous leaves. 
Grows on arid hills , between Pachuca and Moran , alt. 1,300 hex. (7,800 ft.). (Mexico) Shrub. Flowers in 
May. 
Shrub 3 feet high, very much branched; branches spreading divergent, reflexed, rounded, smcoth, 
glabrous, blackish; twigs subangular, pubescent. Leaves sparse, petiolate, densely fasciculate on short¬ 
ened branches, oblong, acute and mucronate, somewhat acute at the base, crenate-serrulate, the teeth with 
glandular midrib, reticulate-veined, prominent below, membranaceous, glabrous, with scattered, very 
minute scurfy dots above, 5 to 6 lines long, 2 to 2% lines wide. Petioles 1 line long, canaliculate, 
puberulous. Stipules linear-subulate, serrulate-glandular below, pubescent, twice as long as the petiole. 
Flowers axillary, solitary, with very short peduncles, scarcely as large as the flower of Amygdalus incana ; 
peduncle scarcely half a line long, thick, glabrous, subtended by several imbricate, ovate, purplish, glabrous 
bracts. Calyx (figs. 1 to 3) subturbinate-campanulate, limb 5-parted, reddish, glabrous, later split around 
above the base and deciduous, with ovate lacinise, denticulate-glandular at the margin, 3-veined, equal, 
reflexed. Petals (fig. 5) five, inserted in the throat of the calyx, alternating with the lacinise of the latter 
and twice as long, unguiculate, obovate, entire (2-parted fide Bonpl.), white, glabrous (this I saw formerly 
in specimens no longer at hand), fallen from the specimens at hand. Stamens (fig. 4) about 14, slightly 
shorter than the lacinise of the calyx; of these 4 inserted in a tube towards the middle; 10 around in a border 
(five opposite the lacinise of the calyx, five opposite the petals). Filaments subulate, glabrous. Anthers 
subrotund, affixed dors^lly, exposed (figs. 6 to 7). deeply trisulcate in front, bilocular, longitudinally 
dehiscent on the inside. Ovary (figs. 8 and 9) free, sessile, oblique ovate, somewhat compressed, shorter 
than the calyx tube, sericeous, unilocular (fig. 10); ovules (fig. n) two, ovate, side by side, suspended below 
the apex, pendulous. Style terminal, filiform, exserted, glabrous. Stigma (fig. 12) dilated, peltate. Fruit 
(not seen) globular, monospemious (fide Bonpl.). 
Varies in a 6-parted calyx. 
