4. Rosa carolina L. (pasture rose)
R. carolina var. grandiflora (Baker) Rehder
Pl. 538 b, 540
e, f; Map 2489
Stems
30–100(–130) cm long, low or weak and spreading to strongly ascending, mostly
slender, dull reddish brown, the relatively few branches with mostly paired
prickles at the nodes, these (2–)3–9 mm long, 1.5–3.0 mm wide, sometimes
slightly to moderately broadened at the base, straight, occasionally
downward-angled or rarely curved, flattened or not, sometimes also with sparse,
scattered bristles between the nodes, rarely unarmed or densely covered
throughout with larger prickles at the nodes and shorter prickles, bristlelike
prickles, and stalked glands between the nodes. Leaves 5–10(–16) cm long, the
petiole and rachis glabrous or less commonly hairy, occasionally with sparse
stalked glands, occasionally with small prickles and/or scattered bristles.
Stipules 10–18(–23) mm long, the margins entire or finely glandular-toothed
toward the tip, the auricle flared, 2–4 mm long. Leaflets (3)5 or 7(9), 18–50
mm long, 9–28 mm wide, the terminal leaflet with a stalk 4–11 mm long, the
blades ovate, elliptic, or lanceolate, angled at the base, angled or tapered at
the sharply or occasionally bluntly pointed tip, the margins relatively
coarsely simply or rarely doubly (or more) toothed with 8–14 teeth per side,
these sometimes gland-tipped, the upper surface dull or slightly shiny, green,
the undersurface glabrous or rarely hairy or glandular on the midvein.
Inflorescences on lateral branches from second year’s stems, of solitary
flowers or less commonly clusters of 2 or 3(–6) flowers, the flower stalks 5–19
mm long, with few to many stalked glands, rarely nonglandular, with usually
several bracts. Flowers not doubled, the hypanthium 4–6(–8) mm long, with
sparse to dense stalked glands, rarely nonglandular, the mouth usually 1.5–2.0
mm in diameter. Sepals 16–22 mm long, 3–4 mm wide, often unequal, some of them
usually extending into dilated, somewhat leaflike tips and with the margins
toothed or with 1 or few pairs of linear lobes, the undersurface nonglandular
or occasionally sparsely glandular, becoming reflexed after flowering, usually
shed by fruit maturity. Petals 15–24 mm long, pink to less commonly reddish
pink, rarely white. Pistils 32–46, the styles free, hairy, not extending or
extending up to 1 mm beyond the mouth of the hypanthium, the mass of stigmas
thus not or only slightly elevated, more or less closing the hypanthium mouth.
Hips 7–14 mm long, 6–15 mm wide, globose to slightly depressed-globose or
rarely ellipsoid, fleshy, the surface dull to more commonly shiny, red to
orangish red, lacking glands or with sparse to dense stalked glands. Achenes
mostly 2–6 (note additional presence of up to 16 undeveloped ovaries), 4–5 mm
long. 2n=28. May–July.
Scattered to
common nearly throughout the state (eastern U.S. west to Minnesota and Texas;
Canada; Mexico). Upland prairies, loess hill prairies, sand prairies, edges and
openings of mesic to dry upland forests, savannas, glades, ledges and tops of
bluffs, banks of streams, and rarely bottomland prairies, levees, and swamps;
also pastures, old fields, fencerows, cemeteries, railroads, and roadsides.
Rosa
foliolosa Nutt. is a
distinctive species related to R. carolina that has a fairly restricted
range in portions of eastern Texas, Oklahoma, and western Arkansas. It differs
from R. carolina in its narrower leaflets, shorter (6–14 mm) stipules,
and white corollas. W. H. Lewis (1958a) reported R. foliolosa from
northeasternmost Oklahoma, close to the Missouri border, and suggested that it
might be discovered in southwestern Missouri in the future. This is the only
native American rose with routinely white corollas, which is a feature that
collectors should focus on in searching for Missouri populations. Other
normally pink-flowered roses do have rare forms with white corollas. However,
these normally exist as white-flowered individuals within pink-flowered populations.
Rosa carolina is a morphologically variable and
broadly distributed tetraploid taxon that can be difficult to distinguish from R.
arkansana. For further discussion, see the treatment of that species. W. H.
Lewis (2008) treated R. carolina as comprising three subspecies. The
third subspecies, ssp. mexicoensis W.H. Lewis, occurs in Mexico and
differs in its smaller, more densely branched habit, smaller leaves, and more
finely and doubly toothed leaflet margins with the teeth gland-tipped.