Rubus trivialis
Rubus flagellaris
southern dewberry
northern blackberry, northern dewberry, ronce à flagelles, whiplash dewberry
biennial, initially low-arching, then falling and creeping (or climbing through other vegetation), glabrous or moderately hairy, sparsely to densely short- to long-stipitate-glandular, not pruinose;
prickles moderate to dense, recurved, sometimes distally slender, 1–4 mm, broad-based;
bristles absent or sparse to dense, erect to retrorse, red to purple, rarely green, slender, weak, gland-tipped.
biennial, usually creeping, sometimes low-arching and then creeping flowering branches usually erect, glabrous or densely hairy, eglandular or sparsely sessile- to short-stipitate-glandular, not pruinose;
prickles sparse to dense, hooked, sometimes distally slender, 1–4 mm, broad-based;
bristles absent.
persistent or semipersistent, ternate to palmately compound, lustrous;
stipules filiform, linear, or lanceolate, 2–12(–15) mm;
leaflets 3–5, terminal narrowly elliptic or ovate to obovate, 2–8.5 × 0.7–4.5 cm, base rounded to cuneate, unlobed, margins moderately to coarsely serrate to doubly serrate, apex acute to acuminate, abaxial surfaces with hooked prickles on midvein, glabrous or sparsely to moderately hairy, eglandular or sparsely short-stipitate-glandular along central vein.
deciduous, some sometimes semipersistent, ternate or palmately compound, not lustrous;
stipules filiform or linear to lanceolate, 3–20 mm;
leaflets 3–5, terminal ovate or elliptic to suborbiculate, 3–11 × 2–7.5 cm, base broadly cuneate or rounded to shallowly cordate, usually unlobed, rarely shallowly lobed, margins moderately to coarsely serrate to doubly serrate or serrate-dentate, apex acute or acuminate to short-attenuate, abaxial surfaces with prickles on midvein or unarmed, sparsely to moderately hairy, eglandular or sessile- or short-stipitate-glandular along largest veins.
terminal on short shoots, usually appearing axillary, 1(–3)-flowered.
terminal on short shoots, usually appearing axillary, 1–3(–8)-flowered, racemiform.
prickles and, often, bristles moderate to dense, recurved, moderately to densely hairy, sparsely to moderately sessile- to short-stipitate-glandular.
unarmed or prickles sparse to moderate, retrorse to hooked, moderately to densely hairy, usually sparsely to densely sessile- or short-stipitate-glandular, rarely eglandular.
bisexual;
petals white to pink, elliptic to obovate, 10–16(–25) mm;
filaments filiform;
ovaries glabrous.
bisexual;
petals white, elliptic, obovate, or oblanceolate, 8–20 mm;
filaments filiform;
ovaries glabrous.
black, globose to ovoid, 1–1.5(–2) cm;
drupelets 10–50, strongly coherent, separating with torus attached.
black, sometimes dark red, globose to cylindric, 1–2 cm;
drupelets 10–40, strongly coherent, separating with torus attached.
= 14.
= 14, 21, 28, 35, 42, 49, 56, 63.
Rubus trivialis
Rubus flagellaris
Rubus trivialis is distinguished from other species of Rubus by its frequently glandular-bristly and generally creeping stems, abundant recurved prickles, and typically persistent or semipersistent, lustrous primocane leaves with relatively narrow leaflets. Although emerging primocanes typically reach to 30 cm above the ground, vigorous plants can have new primocanes standing erect to 70 cm that later fall to the ground or onto adjacent vegetation as they continue to enlarge. L. H. Bailey (1941–1945) believed that there was no clear separation between members of sect. Persistentes Fernald (referred to by Bailey as sect. Verotriviales [illegitimate sectional name for R. trivialis and associated species]) and sect. Procumbentes (by Bailey as sect. Flagellares; including R. flagellaris and related species). All characteristics that he recognized for distinguishing sect. Persistentes from sect. Procumbentes are often present in the latter, with the exception of hispid-setose stems, and glabrous plants of R. trivialis are difficult to distinguish from some plants of R. flagellaris; to include the latter species within the former would be reasonable.
Rubus ×inferior L. H. Bailey is a putative hybrid of R. trivialis and R. cuneifolius.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Rubus flagellaris is extremely polymorphic, ranging from plants with low-arching (and later creeping) stems and relatively few prickles to low, creeping plants with abundant prickles. Individual plants in some years will produce abundant, arching, poorly armed stems, and in others creeping, well-armed stems. Prickle shape also varies in these plants both within a year and among different years. Local variants seem to readily intergrade with other variants; over the entire North American range of what would be known as sect. Procumbentes (Rydberg) L. H. Bailey [= sect. Flagellares (L. H. Bailey) L. H. Bailey], a continuum of variation seems to be common. sect. Procumbentes (Rydberg) L. H. Bailey [by Bailey as sect. Flagellares (L. H. Bailey) L. H. Bailey
Apparent consistent features of Rubus flagellaris are terete primocanes to 7 mm diam. near the base and presence of rigid, hooked primocane prickles to 4 mm. Primocanes that tip-root and are low and long-running are nearly consistent features of R. flagellaris. Flower number per inflorescence throughout most of the geographic range of R. flagellaris is one to three or, rarely, five; in the far western part of the range (as R. arizonensis [= R. oligospermus Thornber ex Rydberg, name illegitimate]) up to eight flowers per inflorescence have been reported.
Rubus flagellaris lacks pruinose fruits and stems and is similar in general appearance to the introduced R. caesius.
Rubus vagus L. H. Bailey is an illegitimate later homonym that applies here. Rubus longipes Fernald is an illegitimate name that applies here.
The following nothospecies names are based on putative hybrids involving Rubus flagellaris and: R. allegheniensis (R. ×boyntonii Ashe, R. ×fraternalis L. H. Bailey [based on R. ×fraternus Brainerd & Peitersen (not R. fraternus Gremli)], R. ×licens L. H. Bailey; R. ×ostryifolius Rydberg); R. canadensis (R. ×lepagei L. H. Bailey, R. ×rixosus L. H. Bailey); R. hispidus (R. ×ambigens Fernald, R. ×distinctus L. H. Bailey, R. ×elongatus Brainerd & Peitersen [not R. elongatus Smith], R. ×emeritus L. H. Bailey, R. ×furtivus L. H. Bailey, R. ×kalamazoensis L. H. Bailey, R. ×permixtus Blanchard, R. ×rosendahlii L. H. Bailey, R. ×segnis L. H. Bailey, R. ×varus L. H. Bailey, R. ×vigoratus L. H. Bailey); R. pensilvanicus (R. ×akermanii Fernald, R. ×darlingtonii L. H. Bailey, R. ×dissitiflorus Fernald, R. ×hypolasius Fernald, R. ×janssonii L. H. Bailey, R. ×largus L. H. Bailey, R. ×recurvicaulis Blanchard, R. ×rossbergianus Blanchard); R. setosus (R. ×alter L. H. Bailey, R. ×arcuans Fernald & H. St. John, R. ×biformispinus Blanchard, R. ×bigelovianus L. H. Bailey, R. ×bracteolifer Fernald, R. ×jacens Blanchard var. specialis L. H. Bailey, R. ×laevior (L. H. Bailey) Fernald [based on R. permixtus var. laevior L. H. Bailey], R. ×multiformis Blanchard, R. ×setospinosus L. H. Bailey, R. ×severus Brainerd ex Fernald).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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