3. Viburnum lentago L. (nannyberry, sheepberry, wild raisin)

Map 1439, Pl. 338 a, b

Plants shrubs or small trees 2–6(–10) m tall. Bark firm, not peeling, relatively smooth to finely roughened or warty on younger branches, sometimes forming small plates or flakes on older trunks, gray to grayish black. Winter buds oblong-conical, often somewhat flattened, with a pair of scales, these valvate (the margins touching but not overlapping), glabrous, somewhat sticky. Stipules absent. Petioles 14–25 mm long, with well-developed wings 0.5–1.0 mm wide flanking the ventral groove, especially toward the tip, these undulate or irregularly curled, moderately to densely pubescent with microscopic, red, stellate hairs when young, becoming glabrous or nearly so at maturity, lacking prominent glandular swellings near the tip. Leaf blades 6.5–10.5 cm long, 3.5–7.5 cm wide, unlobed, relatively thin and papery, broadly ovate-elliptic to elliptic or oblong-elliptic, rounded to short-tapered at the base, abruptly contracted to a slender, long-tapered, sharply pointed tip, the margins finely toothed with the teeth 5–11 per cm, numerous on each side, the surfaces glabrous or with scattered microscopic, red, stellate hairs when young, pinnately veined, the secondary veins evenly spaced, curved or arched toward the tip, looping and joined with adjacent veins into a network, not reaching the margin. Inflorescences sessile, with 3–5(–7) primary branches, these glabrous or with scattered microscopic, red, stellate hairs, the marginal flowers fertile and similar to the other flowers. Ovaries glabrous. Fruits 7–18 mm long, ellipsoid to nearly spherical, bluish black, glaucous. Nutlet 8–11 mm long, yellowish brown. 2n=18. May–June.

Uncommon, known thus far natively only with surety from Schuyler County; introduced sporadically elsewhere (northeastern U.S. west to Montana and Colorado, south locally to Alabama; Canada). Bottomland forests, mesic upland forests, banks of streams and rivers, and fens.

Steyermark (1963) regarded this species as occurring in native populations only in Schuyler County. He discussed historical collections from Franklin and St. Louis Counties, which he dismissed as either misdeterminations or representing cultivated plants. However, he overlooked an additional historical collection from St. Louis County that may represent a native occurrence, although the specimen collected in 1891 by Noah Glatfelter at Meramec Highlands bears no label data to address this situation.

Viburnum lentago and its close relatives V. prunifolium and V. rufidulum are members of section Lentago, which comprises six total species distributed in the U.S., Canada, and Mexico. Incomplete specimens can be difficult to determine to species within the section. Steyermark (1963) stated that V. lentago differs from V. prunifolium and V. rufidulum in having teeth that point straight out from the leaf margin (vs. angled toward the apex). However, serration in V. lentago and its relatives is more variable than he indicated, and this character should not be used to discriminate among taxa in the section.

Steyermark (1963) discussed the fall foliage, which turns a dull or deep purplish red with dull green to rose-colored highlights. He noted that the species can spread by root suckers to form thickets, and that in cultivation it is prone to attack by aphids, scales, and leaf hoppers, but he recommended it for cultivation anyway.