8. Viburnum rafinesquianum Schult. (downy arrowwood)
V.
rafinesquianum var. affine
House
Map 1444, Pl.
338 h
Plants shrubs 1–2
m tall. Bark firm, not peeling, usually relatively smooth to finely roughened
or warty on younger branches, rarely somewhat peeling in papery sheets,
becoming somewhat fissured on older stems, gray or grayish brown to reddish
brown. Winter buds ovoid-conical, slightly flattened, with 2 pairs of
overlapping scales, glabrous, not or only slightly sticky. Stipules often
present but usually shed early, partially fused to the basal portion of the
petiole, linear, hairy and usually also glandular. Petioles 3–15(–22) mm long,
unwinged, sparsely to moderately hairy, mostly along the ventral groove,
lacking prominent glandular swellings near the tip. Leaf blades (4–)6–10 cm
long, 3–7 cm wide, unlobed, relatively thin and papery, ovate to broadly
oblong-ovate or occasionally nearly circular, rounded to truncate or shallowly
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, 7–12(–14)
on each side, the upper surface glabrous or more commonly with scattered,
unbranched hairs, the undersurface sparsely to moderately pubescent along the
main veins with mostly unbranched hairs and usually also with small patches of
densely woolly hairs in the axils of the main veins, 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 sessile or short- to long-stalked, with (3–)5–7 primary
branches, these with dense, minute glands at flowering, the marginal flowers
fertile and similar to the other flowers. Ovaries with dense, minute glands.
Fruits 6–9 mm long, ellipsoid, oblong-ovoid, or nearly spherical, bluish purple
to purplish black, not glaucous. Nutlet 6.0–7.5 mm long, yellowish brown to
dark reddish brown. 2n=36. May–June.
Scattered mostly
in the eastern half of the state, uncommon or absent from most of western
Missouri (eastern U.S. west to North Dakota and Oklahoma; Canada). Bottomland forests,
mesic to less commonly dry upland forests, banks of streams and rivers, and
bases and ledges of bluffs.
Plants with leaf
pubescence absent or limited to the veins have been called var. affine
and appear to be the more common phase in Missouri. However, because of the
large number of specimens with seemingly intermediate levels of hairiness, it
has not been possible to accept the varieties in the present treatment.
Steyermark (1963) noted that the fall foliage of this species is attractive,
varying from dull purplish red to dull purple with reddish highlights.