5. Rhamnus lanceolata Pursh

R. lanceolata ssp. glabrata (Gleason) Kartesz & Gandhi

R. lanceolata var. glabrata Gleason

Pl. 522 a–c; Map 2400

Plants shrubs, 1–3 m tall, dioecious. Main stems usually several, the branches all ascending to loosely ascending and elongate, none of them thorn-tipped. Bark gray, sometimes with lighter blotches, relatively smooth, but with relatively prominent lenticels in raised cross lines, somewhat peeling on older, larger stems. Twigs slender, reddish brown, becoming gray with age, initially often minutely hairy, but soon glabrous or nearly so, the winter buds ovate in outline, somewhat flattened, with several overlapping scales, these reddish brown, glabrous except for sparse, marginal hairs near the tip. Leaves alternate (occasionally a few appearing subopposite), the petioles 3–9 mm long. Leaf blades 2–8 cm long, 2–4 times as long as wide, rounded or angled at the base, angled or tapered to a bluntly or more commonly sharply pointed tip, the upper surface green to dark green, glabrous or minutely hairy, mostly along the veins, shiny, the undersurface light green, glabrous to densely and minutely hairy, especially along the veins, the lateral veins mostly 4–7 pairs, these more or less arched toward the blade tip. Inflorescences axillary, small clusters of 2 or 3 staminate flowers or solitary (rarely paired) pistillate flowers, the clusters sessile, the individual flower stalks 2–3 mm long. Flowers imperfect. Sepals 4, 1.3–2.0 mm long. Petals 4, 1.0–1.2 mm long in staminate flowers, 0.5–0.9 mm long in pistillate flowers, broadly obovate, notched at the tips. Style noticeably 2-branched toward the tip. Fruits 4–7 mm long, globose, with 2 stones, black at maturity. April–June.

Scattered nearly throughout the state, but apparently absent from the Mississippi Lowlands Division (eastern U.S. west to South Dakota and Texas). Glades, upland prairies, ledges and tops of bluffs, banks of streams and rivers, savannas, and openings of dry upland forests.

This species can easily be overlooked in its natural habitats. In the field, plants sometimes are mistaken for Ilex decidua Walter (deciduous holly, Aquifoliaceae). Plants with the leaf blades glabrous or nearly so on the undersurface, which are the common phase in Missouri, have been called var. glabrata. Plants with relatively densely and minutely hairy leaves (var. lanceolata) are far less common and occur mainly in the eastern half of the state. In her taxonomic revision of the R. serrata complex, Johnston (1975) considered these to represent merely trivial forms of a variable species. Intermediate plants are relatively widespread in the midwestern states.