4. Viburnum molle Michx. (Missouri arrowwood, Kentucky viburnum)

Map 1440, Pl. 338 g

Plants shrubs 2–6 m tall. Bark peeling in papery sheets, gray or grayish brown to yellowish brown. Winter buds ovoid-conical, slightly flattened, with 2 pairs of overlapping scales, glabrous, not or only slightly sticky. Stipules usually present but often shed early, partially fused to the basal portion of the petiole, linear, glandular. Petioles 23–50 mm long, unwinged, with sparse, minute, stalked glands, lacking prominent glandular swellings near the tip. Leaf blades 5–14 cm long, 5–12 cm wide, unlobed, relatively thin and papery, broadly ovate or broadly triangular-ovate to broadly heart-shaped or nearly circular, mostly deeply cordate at the base, angled or short-tapered to a bluntly or more commonly sharply pointed tip, the margins coarsely toothed with the teeth 1–3 per cm, 18–35 on each side, the upper surface glabrous or more commonly inconspicuously and minutely glandular along the main veins, the undersurface sparsely to moderately pubescent with short, unbranched or few-branched hairs, most abundantly along the main veins, sometimes also sparsely and minutely glandular, often with 3–5 secondary veins on each side crowded near the base of the midvein, pinnately veined above the base, the secondary veins straight, often dichotomously branched but not forming a network, extending to the leaf margin, each branch ending in a tooth. Inflorescences short- to more commonly long-stalked, with 5–7 primary branches, these with moderate to dense, minute glands at flowering, sometimes also with scattered, unbranched hairs, the marginal flowers fertile and similar to the other flowers. Ovaries with dense, minute glands. Fruits 7–11 mm long, ellipsoid to oblong-ellipsoid and slightly flattened, bluish black, not glaucous. Nutlet 6–10 mm long, yellowish brown to reddish brown. 2n=18, 36. May–June.

Scattered in the Ozark and Ozark Border Divisions north locally to Lincoln County (Pennsylvania to Tennessee west to Iowa and Arkansas). Bases and ledges of limestone and dolomite bluffs and adjacent bottomland and mesic upland forests.

This species often spreads by underground runners to form clonal colonies. It can become a dominant species on talus slopes and ledges of wooded bluffs. Plants with the pubescence of the leaf undersurface confined to the major veins have been called f. leiophyllum Rehder.