21. Rubus roribaccus (L.H. Bailey) Rydb. (Lucretia dewberry)

Rubus occidualis (L.H. Bailey) L.H. Bailey

Map 2519

Canes to 250 cm long and 50 cm tall, 2.5–5.0 mm in diameter. Prickles moderate to dense, 1.0–4.5 per cm of cane, 1.0–3.5 mm long. Petioles with dense, nonglandular hairs, armed with downward-curved prickles to 2 mm long. Stipules 12–18 mm long, linear to linear-lanceolate, sometimes notched. 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–)7.5–9.5(–11.0) cm long and (5.5–)6.0–8.5(–9.0) cm wide, nearly orbicular to ovate or ovate-elliptic, sometimes lobed, cordate to truncate at the base, tapered to a sharply pointed tip, the leaflet stalk about 1/4–2/5 as long as the leaflet blade; middle leaflets elliptic to elliptic-obovate, rounded to angled at the base, short-tapered to a sharply pointed tip; basal leaflets, when 3 leaflets are present, ovate, rounded at the base, short-tapered to a sharply pointed tip, sessile, when 5 leaflets are present, elliptic to elliptic-obovate, angled at the base, angled to a sharply pointed tip, short-stalked to sessile. Inflorescences (4.0–)6.5–25.0(–35.0) cm long, with (1–)3–5(–8) flowers on long, ascending stalks, with 2–7 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 7–16 mm long, 4–5 mm wide, triangular-ovate to elliptic, tapered to a sharply pointed tip or expanded into a lobed, leafy tip. Petals 12–20 mm long, obovate to broadly obovate. Fruits 13–25 mm long, 15–25 mm wide, globose to cylindric or long-conic. 2n=49. April–June.

Scattered nearly throughout the state but apparently absent from most of the western portion of the Glaciated Plains Division (northeastern U.S. west to Iowa, Kansas, and Oklahoma). Openings of mesic to dry upland forests, upland prairies, banks of streams and rivers, margins of ponds and sinkhole ponds, ledges of bluffs; also pastures, old fields, old mines, cemeteries, railroads, roadsides, and open, disturbed areas.

Large-fruited selections of R. roribaccus have been cultivated and may escape or persist from gardens. This species has escaped from cultivation in Australia (Evans et al., 2007).