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.