Pedraza-Peñalosa, Paola & Luteyn, James L. 2011. Andean
Ericaceae
Description - Vaccinio sphyrospermoidi marginibus folii crenatis, pilis fasciculatis, corollis rotatis, viridibus similis, sed floribus subsessilifloris 5-7-meris (non pedicellatis, [4-] 5-meris), calycibus glabris (non confertim hirsutis) differt. Terrestrial shrubs , to 2 m tall. Twigs ridged, pilosulose, the hairs simple, unicellu- lar, and eglandular, the mature stems more or less terete, the bark light brown, fissured, glabrescent; buds axillary, prophylls 2, opposite, valvate, ovate, inconspicuous, 1-1.2 mm long, apically acute, marginally ciliolate at apex, the hairs simple, unicellular, and eglandular, glabrous. Leaves alternate, ascendent; petioles not twisted, subterete, 1.1 -2.7 (-3.4) mm long, inconspicuously glabrescent, the hairs simple, unicellular and elgnadular; blades corieacous, ovate or elliptic, 1-2.5 x 0.4 - 1 cm, basally rounded or cuneate, marginally thickened and cren- ulate, the teeth terminated in a caducous seta, with the tendency to be slightly revolute basally when dry (but flat in fresh material), apically ciliolate in young leaves with hairs simple, unicellular and eglandu- lar, apically obtuse or acute, mucronate, the muero fragile, short, 0.4-0.8 mm long, glabrescent above (especially over midrib) with hairs simple, unicellular and eglandu- lar, almost glabrous beneath with few clustered unicellular/eglandular hairs radiat- ing around a single multicellular/glandular hair; venation obscure when dry with only the midrib impressed adaxially. Inflorescen- ces axillary, 2 -flowered fascicles or some- times flowers apparently solitary, flowers subsessile; all bracts undifferentiated, char- taceous, ovate or elliptic, gradually varying in size, 0.8-1.5 x 0.6-1.3 mm, apically obtuse, marginally eciliate, glabrous; ped- icels subterete, 1-1.5 mm long, articulate with calyx, glabrous except for simple, multicellular and glandular hairs at articu- lation; bracteoles 2, persistent, opposite or subopposte, inserted at base of pedicel, similar to bracts, ovate, 1.4x0.6-0.8 mm, marginally ciliolate with hairs simple, uni- cellular and eglandular, apically acute, glabrous. Flowers 5-7-merous, haplostemo- nous. Calyx aestivation valvate, campanu- late overall, 3.8^.3 mm long, glabrous; tube obconic, terete, 2.0-2.8 mm long; limb spreading, 1.5-1.9 mm long; lobes deltate, 1 .3-1 .5x1 .3-1 .5 mm, marginally eciliate, apically acute; sinuses acute. Corolla aesti- vation valvate, light green, rotate, 2.7- 3.2 mm long, 2.7-3 mm diam., glabrous within and without; lobes ovate, deep, 1.7- 2.1x1.8-2.7 mm, apically acute, strongly reflexed. Stamens 5-7, equal, basally adher- ent to corolla, exposed, 1.5-1.6 mm long; filaments equal, distinct, long-triangular, incurved, 1-1.1 mm long, glabrous; anthers equal, distinct, 0.8-1 mm long; thecae 0.7- 0.8 mm long, inconspicuously papillose; tubules 2, distinct to base, inconspicuous, very reduced, 0.1-0.15 mm long, dehiscing by terminal pores, 0.2 mm diam. Ovary 4 - locular, locules sometimes of variable size, placentation axile; nectariferous disc pulvinate, glabrous; style exposed, filiform, terete, 1.5 - 1.9 mm long, glabrous, stigma simple. Berry spherical, 5.5 - 7.5 mm diam., dark purple; seeds many per locule, but apparently few fully developed, ellipsoid, 1.6 x 0.9 mm, with mucilaginous coat, embyro white.
Phenology. - Flowering collections have been made in February-March and June.
Etymology. - The new species is named for Ken Young, who, along with Blanca León, has gone out of his way to collect many specimens of Vaccinium.Vaccinium youngii is characterized by hav- ing small, ovate to elliptic and marginally crenulate leaves, bearing clustered hairs abax- ially; 5-7-merous and haplostemonous flowers; small, rotate, green, and deeply lobed corollas; short pedicels; and stout staminal anthers with inconspicuous, reduced tubules. In its overall appearance, this species may be confused with V. sphyrospermoides , which also has crenulate leaves with clustered hairs and green, rotate corollas. Vaccinium youngii, however, has narrower (0.4-1 vs. [0. 6-] 1-1.3 cm in V. sphyrospermoides) leaves that are crenulate along the entire leaf (vs. mostly distally) and apically shortly mucronate (vs. rarely incon- spicuously apiculate); its flowers are subsessile (pedicel 1-1.5 mm vs. 4-7 mm long), 5-7- merous (vs. [4-]5-merous), with glabrous calyces (vs. densely and persistently short- hirsute) and apparently more rotate corollas (vs. rotate-campanulate). The crenulate leaves of V. youngii also remind us of broad - leaved specimens of V. didymanthum Dunal, but when corollas are present the two species are obviously veyr different (rotate and green vs. cylindrical and white, respectively).