4. Packera paupercula (Michx.) W.A. Weber & Á. Löve (northern ragwort)
Senecio
pauperculus Michx.
S.
pauperculus var. balsamitae
(Muhl. ex Willd.) Fernald
Pl. 298 i, j;
Map 1254
Plants
perennial, from a short, stout to slender, erect to horizontal rootstock, often
producing a short to moderately creeping rhizome, rarely producing short
stolons. Stems mostly 1, occasionally 2 or 3, 10–60 cm long, often pubescent
with dense, felty hairs in the axils of the basal leaves, the portion above the
base thinly pubescent to glabrous, but sometimes with cobwebby patches of dense
hairs in the leaf axils. Basal leaves usually present at flowering,
long-petiolate, the petioles glabrous or sparsely hairy above the usually
woolly or cobwebby base, the blades 1–8 cm long, unlobed or less commonly with
few narrow, irregular lobes toward the base, narrowly ovate-elliptic to
oblanceolate, mostly truncate to cordate at the base (rarely narrowed), the
tissue not extending along the petiole or else extending along only the
terminal portion of the petiole, rounded to bluntly pointed at the tip, the margins
with relatively sharp, sometimes irregular teeth (rarely scalloped), the
undersurface glabrous or sparsely to moderately (but inconspicuously) hairy,
the upper surface glabrous. Stem leaves gradually reduced toward the stem tip,
sessile or nearly so, the blades mostly deeply pinnately lobed, sometimes
irregularly so, the margins otherwise relatively sharply toothed, the surfaces
glabrous except sometimes for patches of dense, cobwebby hairs at the very
base. Involucre 4–7 mm long, glabrous or somewhat cobwebby-hairy near the base.
Ray florets usually 7–13, the lobe 5–10 mm long. Fruits 2.5–3.0 mm long,
glabrous or hairy along the ribs. 2n=44, 88. April–August.
Scattered,
mostly in the northern half of the state (eastern U.S. west to Washington and
Arizona [but absent from most of the Great Plains]; Canada). Upland prairies,
loess hill prairies, openings of mesic to dry upland forests, ledges of bluffs,
and rarely bottomland forests; also pastures, railroads, and roadsides.
Packera
paupercula varies
relatively greatly in overall size, leaf shape, and pubescence density. For
some specimens, it is virtually impossible to distinguish this species from the
closely related P. plattensis. Barkley (1963) detailed the situation for
plants from Wisconsin, where the problems are similar to those in Missouri. In
general, both species usually may start out relatively evenly and densely
hairy, but plants of P. plattensis tend to remain more persistently
woolly or cobwebby-hairy than do plants of P. paupercula. Also, plants
of P. paupercula in Missouri tend to produce short rhizomes more
frequently, whereas those of P. plattensis tend to produce slender
stolons more regularly. It should be noted that Allison Mahoney of Minnesota
State University and Robert Kowal of the University of Wisconsin have annotated
some Missouri specimens of stoloniferous, relatively small-leaved plants
previously referred to P. plattensis by Barkley (1962, as Senecio)
as representing an as-yet unpublished variety of P. paupercula. The name
Senecio pseudotomentosus may in fact apply to this variant, but Barkley
referred that name to synonymy under P. plattensis. Evidently there is
still substantial disagreement on species limits within the complex among
specialists on the group.