20. Rubus meracus L.H. Bailey

R. frustratus L.H. Bailey

R. kelloggii L.H. Bailey

Map 2518

Canes to 250 cm long and 60 cm tall, 2.5–4.0 mm in diameter. Prickles usually moderate, 1–4 per cm of cane, 1.5–2.5 mm long. Petioles with dense, nonglandular hairs, armed with downward-curved prickles to 2 mm long. Stipules 12–15 mm long, linear to linear-lanceolate. Primocane leaves with 3 or 5 leaflets, margins coarsely and sharply toothed, the upper surface thinly hairy, the undersurface velvety hairy. Central primocane leaflets (6.5–)7.0–9.0 cm long and (4–)5–6 cm wide, elliptic, rounded at the base, tapered to a short, sharply pointed tip, the leaflet stalk about 1/5–3/10 as long as the leaflet blade; middle leaflets elliptic-obovate, angled at the base, short-tapered to a sharply pointed tip, stalked; basal leaflets, when 3 leaflets are present, ovate, often with asymmetric lobes, rounded at the base, angled to tapered to a sharply pointed tip, short-stalked, when 5 leaflets are present, elliptic to elliptic-obovate, angled at the base, angled to a sharply pointed tip, sessile.Inflorescences 5–20 cm long, with 1–6(–8) flowers on long, ascending stalks, with 2–6 leafy bracts, these about evenly divided between simple bracts and those with 3 leaflets; flower and inflorescence stalks with dense, nonglandular hairs and downward-angled to downward-curved prickles. Sepals 7–9 mm long, 3.0–4.5 mm wide, triangular-elliptic, tapered to a sharply pointed tip or abruptly tapered to a short, slender point. Petals (9–)12–20 mm long, obovate to broadly obovate. Fruits 12–17 mm long, 10–15 mm wide, globose to short-cylindric. 2n=49. April–May.

Uncommon, mostly south of the Missouri River (eastern U.S. west to Kansas and Oklahoma). Mesic to dry upland forests, upland prairies, sand prairies, savannas, glades, and margins of sinkhole ponds; also roadsides.

Two taxa here treated as synonyms of R. meracus (Widrlechner, 1998), R. frustratus and R. kelloggii, were described from Missouri, with the type material of R. frustratus collected by B. F. Bush in Cooper County in 1935 (L. H. Bailey, 1943a) and that of R. kelloggii by J. H. Kellogg in Stoddard County in 1933 (L. H. Bailey, 1945).

This dewberry can closely resemble R. roribaccus. The primary difference is expressed in the narrower leaflets of R. meracus. Some Missouri collections are difficult, if not impossible, to assign to one species or the other with certainty, and the county distribution map for R. meracus may contain a few records that will in the future be redetermined as R. roribaccus.. This is especially true of fragmentary collections and of late-season primocanes, which can have relatively narrow leaflets in both taxa.