1. Krigia biflora (Walter) S.F. Blake var. biflora (two-flowered Cynthia, orange dwarf
dandelion)
K. biflora f. glandulifera Fernald
Pl. 257 j, k;
Map 1072
Plants
perennial, the short rootstock with fibrous roots, the main roots often
slightly fleshy. Stems 1 to few, 10–60 cm long, erect or ascending, with few to
several ascending branches from above the midpoint, glabrous or sparsely to
moderately pubescent toward the branch tips with spreading, gland-tipped hairs,
occasionally somewhat glaucous. Leaves basal and usually 1–5 alternate along
the lower stems, the primary (and sometimes also secondary) branch point with 1
or 2 well-developed, bractlike leaves, the basal and lower stem leaves mostly
short- to more commonly long-petiolate (the petiole sometimes winged), those
higher on the stem abruptly different, sessile with rounded, clasping bases.
Blades of basal and lower stem leaves 2–10 cm long, broadly obovate to
oblong-oblanceolate, entire, wavy, toothed, or uncommonly shallowly to deeply
pinnately lobed, the teeth spreading, mostly broadly triangular-pointed, the
lobes usually oblong-rounded, the leaf tip rounded to bluntly pointed, the
surfaces glabrous, usually at least the undersurface glaucous. Blades of median
and upper stem leaves similar to the others but linear to narrowly
oblong-ovate. Involucral bracts 10–18, 7–11 mm long, lanceolate, flat (not
keeled), glabrous, withering and becoming reflexed with age. Ligulate florets
25–60. Corollas 12–25 mm long, yellowish orange to orange. Pappus of 20–40
bristles and 10(–15) short, inconspicuous scales, the bristles 4.0–5.5 mm long,
off-white to very light tan, the scales 0.3–0.5 mm long, mostly lanceolate,
transparent. Fruits 2–3 mm long, more or less cylindrical (slightly expanded at
the tip, slightly tapered at the base), more or less circular in cross-section,
with 12–15 blunt, broad ribs, these microscopically roughened or barbed,
reddish brown to dark brown. 2n=10, 20. May–August.
Scattered in the
Ozark and Ozark Border Divisions and the eastern portion of the Glaciated
Plains; uncommon in the Mississippi Lowlands Division (eastern U.S. and
adjacent Canada west to Minnesota, Kansas, and Oklahoma). Mesic to dry upland
forests, upland prairies, margins of ponds and sinkhole ponds, and banks of
streams; also pastures and roadsides.
Plants that
occur disjunctly in portions of Arizona, Colorado, and New Mexico consistently
have slightly smaller leaves and shorter stems than those in the main portion of
the species’ distribution. These have been segregated as var. viridis
(Standl.) K.-J. Kim, although whether these differences are due to
environmental or genetic variation has not been well studied.