10. Salix petiolaris Sm. (meadow willow)

S. gracilis Andersson

S. gracilis var. textoris Fernald

Pl. 556 a–c; Map 2582

Plants shrubs, 1–3(–6) m tall, sometimes clonal from suckers. Trunks with the bark relatively smooth or somewhat roughened, on older trees becoming flaky, grayish green to reddish brown, on older trunks becoming brown. Branches flexible at the base, reddish brown to dark purple. Branchlets yellowish to reddish brown, not or only slightly glaucous, sparsely to densely velvety-hairy. Winter buds blunt at the tip, the scale margins fused. Leaves alternate. Petioles 3–12 mm long, lacking glands, the upper side usually hairy. Stipules minute or absent. Leaf blades 3–15 cm long, mostly 5–9 times as long as wide, very narrowly elliptic to narrowly oblong-elliptic or narrowly oblong-oblanceolate, angled or tapered to a bluntly or sharply pointed tip, angled at the base, the margins flat or slightly rolled under, finely toothed (sometimes entire elsewhere), the upper surface dull or shiny, glabrous or sparsely silky-hairy, the undersurface glaucous, densely pubescent with long, silky hairs, sometimes becoming nearly glabrous with age. Catkins flowering as the leaves appear, on distinct, leafy, flowering branchlets; the bracts 1–2 mm long, entire, rounded at the tip, tawny, often pinkish-tinged or paler toward the margins, sparsely and evenly hairy, not persistent at fruiting; the staminate catkins 1–3 cm long; the pistillate catkins 1–4 cm long. Staminate flowers with 2 stamens, the filaments free, hairy at the base; nectary 1. Pistillate flowers with the styles fused to the tip or nearly so, often minutely branched at the tip, the stigmas 2, short, linear; nectary 1. Fruits 5–9 mm long, on stalks 1.5–4.0 mm long. 2n=38. April–June.

Uncommon, known thus far from a single historical collection from Dent County (northeastern U.S. west to South Dakota and Nebraska, also disjunct in Colorado and Missouri; Canada). Banks of streams and rivers.

Steyermark’s (1963) report of the isolated occurrence of this species in Dent County is still the only verified specimen of S. petiolaris from Missouri. However, the species should be searched for in the northeastern portion of the state. A specimen at the Missouri Botanical Garden Herbarium collected in 1991 in northern Schuyler County along the Iowa border (Ladd & Heumann 15127B) appears to represent the hybrid Salix famelica × S. petiolaris. The locality, known as State Line Fen, harbors a diversity of willows, but neither of the parents has yet been documented from the site. More intensive inventory of Salix species should be conducted at this fen. This interspecific hybrid resembles S. famelica in its well-developed stipules on later leaves and its yellowish brown branchlets. It resembles S. petiolaris in producing rust-colored hairs on the juvenile leaves and is intermediate in leaf shape and in ovary pubescence.