Rubus trivialis
Rubus nutkanus
southern dewberry
thimbleberry
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, erect, sparsely hairy, glabrescent, moderately stipitate-glandular, glands yellowish to reddish, not pruinose.
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, simple;
stipules lanceolate to ovate, 5–15 mm;
blade orbiculate to reniform, 5–20 × 5–25 cm, base cordate, palmately, shallowly to moderately deeply, (3–)5(–7)-lobed, margins coarsely, irregularly serrate to doubly serrate, apex shortly acuminate to obtuse, abaxial surfaces glabrate to densely hairy, sparsely to moderately stipitate-glandular, glands yellowish to reddish.
terminal on short shoots, usually appearing axillary, 1(–3)-flowered.
terminal and axillary, (1–)3–7(–15), cymiform to thyrsiform.
prickles and, often, bristles moderate to dense, recurved, moderately to densely hairy, sparsely to moderately sessile- to short-stipitate-glandular.
sparsely to moderately hairy, moderately to densely stipitate-glandular, glands yellowish to reddish.
bisexual;
petals white to pink, elliptic to obovate, 10–16(–25) mm;
filaments filiform;
ovaries glabrous.
bisexual;
petals white, broadly obovate, (10–)14–22(–28) mm;
filaments filiform;
ovaries distally densely hairy, styles clavate, glabrous.
black, globose to ovoid, 1–1.5(–2) cm;
drupelets 10–50, strongly coherent, separating with torus attached.
red, hemispheric, 1–1.8 cm;
drupelets 50–60, coherent, separating from torus.
= 14.
= 14.
Rubus trivialis
Rubus nutkanus
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 nutkanus is distinguished from other flowering raspberries by its erect, unarmed stems, simple leaves, large flowers, white petals, glabrous, clavate styles, and yellowish to reddish stipitate glands covering most plant parts. A hybrid with R. odoratus (R. ×fraseri Rehder) is thought to occur in areas of overlap in northern Michigan (E. G. Voss 1972–1996, vol. 2). Varieties and forms have been described based on indument and glandularity of stems, leaves, petioles, pedicels, and sepals (for example, M. L. Fernald 1950). Different variants often occur mixed in the same population and generally do not correspond to definite geographic regions (N. C. Fassett 1941). Plants from coastal California (considered as var. velutinus) tend to have densely hairy leaf abaxial surfaces; this variation may be environmentally induced; other Rubus species show the same pattern (for example, R. spectabilis var. franciscanus) in that area. Wild thimbleberries are collected in Keweenaw Peninsula, Michigan, and are used in beverages and especially for jam.
Rubus nutkanus is typically associated with western North America but was originally described from plants at its eastern range limit in northern Michigan. The Great Lakes populations are disjunct from western mountain populations by around 600 miles.
The name Rubus parviflorus var. grandiflorus Farwell, which applies here, is illegitimate.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
IL Wildflowers
KS Wildflowers
LA Plants
MO Plants
WildflowerSearch
iNaturalist
USDA Plants Database
CA
OR
Flora NW
MI Flora
MN Wildflowers
PNW Herbaria
SW CO Wildflowers
