7. Rudbeckia missouriensis Engelm. ex C.L. Boynton & Beadle (Missouri coneflower)
Pl. 287 f, g;
Map 1223
R. fulgida Aiton var. missouriensis (Engelm.
ex C.L. Boynton & Beadle) Cronquist
Plants
perennial, with fibrous to somewhat fleshy roots and stout rhizomes (new basal rosettes
occurring immediately adjacent to the older stems). Stems 20–50(–80) cm long,
moderately to densely pubescent with relatively long, spreading hairs, not
glaucous. Leaves all unlobed, tapered or angled at the base, only slightly
expanded at the base and inconspicuously wrapping around the stem, the margins
entire or with a few inconspicuous, sharp teeth, the surfaces moderately to
densely hairy with mostly spreading minutely pustular-based hairs, usually
moderately roughened to the touch, not glaucous, green to grayish green when
fresh. Basal and lowermost stem leaves often present at flowering (or present
on adjacent rosettes), more or less sessile to short- or less commonly
long-petiolate, the blade 5–20 cm long, 5–20 mm wide, broadly linear to
oblanceolate or narrowly spatulate, rounded or more or less angled to a bluntly
pointed tip. Median and upper stem leaves sessile, the blade 2–15 cm long, 4–10
mm wide, linear to narrowly oblong-lanceolate, angled or short-tapered to a
bluntly or sharply pointed tip. Inflorescences usually appearing as strongly
ascending clusters. Involucral bracts 10–20, 6–14 mm long, ovate to lanceolate
or occasionally linear, both surfaces sparsely to densely hairy, the margins
usually with moderate to dense, ascending hairs. Receptacle 8–15 mm long, 10–17
mm in diameter, hemispherical at the start of flowering, then elongating
somewhat and sometimes becoming ovoid. Chaffy bracts subtending only the disc
florets, shorter than the disc florets (including the corolla), short-tapered
to a broadly triangular, usually sharply pointed tip, the outer surface
glabrous (sometimes sparsely hairy toward the base) and often somewhat shiny,
the margins usually glabrous. Ray florets 9–15, the corolla 10–25 mm long, relatively
slender, spreading to slightly drooping at flowering, yellow or less commonly
the basal portion orangish- or reddish-tinged, the outer surface sparsely to
moderately short-hairy. Disc florets numerous, the corolla 3.5–4.5 mm long,
greenish yellow toward the base, dark purple to purplish brown toward the tip,
the lobes ascending at flowering. Stigma lobes relatively short and bluntly
pointed at the tip. Pappus a minute rim or crown. Fruits 1.5–3.0 mm long. 2n=38.
June–October.
Scattered in the
Ozark and Ozark Border Divisions (Oklahoma to Texas east to Illinois, Kentucky,
and Louisiana). Glades, ledges and tops of bluffs, rock outcrops in upland
prairies, and rocky openings of dry upland forests, rarely banks of streams;
also roadsides, usually on limestone and dolomite substrates.
This species is
recognized by its relatively low stature, often large colonies of dense
rosettes, narrow leaves, strongly ascending branches, and relatively small
heads.