5. Packera plattensis (Nutt.) W.A. Weber & Á. Löve (prairie ragwort)
Senecio
plattensis Nutt.
S.
pseudotomentosus Mack.
& Bush
Pl. 298 d–f; Map
1255
Plants perennial
or sometimes biennial, from a short, usually stout, erect to horizontal
rootstock, sometimes producing well-developed stolons. Stems mostly 1,
occasionally 2 or 3, 20–70 cm long, more or less evenly pubescent with dense,
felty hairs when young, the portion above the base sometimes becoming more or
less glabrous at flowering, except sometimes for cobwebby patches in the leaf
axils or at the inflorescence branch points. Basal leaves usually present at
flowering, long-petiolate, the petioles with dense, felty hairs when young, the
blades 1–9 cm long, unlobed or less commonly with few narrow, irregular lobes
toward the base, ovate-elliptic to oblanceolate or rarely nearly circular,
tapered to nearly truncate at the base, rounded to bluntly pointed at the tip,
the margins with relatively sharp, sometimes irregular teeth (rarely scalloped
or nearly entire), the surfaces evenly and more or less persistently pubescent
with dense, felty hairs when young, usually becoming nearly glabrous by
flowering time, except toward the base of the petiole. Stem leaves gradually
reduced toward the stem tip, sessile or nearly so, the blades entire or more
commonly irregularly and usually deeply pinnately lobed, the terminal lobe
ovate to elliptic-obovate (rarely much narrower), longer than wide, the margins
otherwise relatively sharply toothed, the surfaces evenly and more or less
persistently pubescent with dense, felty hairs when young, usually becoming
nearly glabrous by flowering time. Involucre 4–7 mm long, glabrous or somewhat
cobwebby-hairy near the base. Ray florets usually 7–9, the lobe 5–10 mm long.
Fruits 2.5–3.0 mm long, usually hairy along the ribs, occasionally glabrous or
the surface evenly hairy. 2n=46, 92. April–June.
Scattered nearly
throughout the state (Pennsylvania to North Carolina west to Montana and
Arizona; Canada). Upland prairies, loess hill prairies, glades, ledges and tops
of bluffs, openings of mesic to dry upland forests, and rarely stream banks;
also pastures, railroads, roadsides, and open, disturbed areas.
For a discussion
of difficulties in distinguishing this species from the closely related P.
paupercula, see the treatment of that species.