Rayless Mountain Groundsel

Packera indecora is found at relatively low elevations in eastern Canada and at middle to subalpine elevations in the western cordillera. It closely resembles P. pauciflora and it is often difficult to identify specimens in the herbarium. Biosystematic studies (J. F. Bain and J. Whitton 1994) have indicated that although they are morphologically similar, P. indecora and P. pauciflora have distinctly different physiologies and should be maintained as distinct taxa.

Perennials, 10–100 cm; taprooted (caudices erect to suberect, relatively stout, branched). Stems 1 or 2–3, loosely clustered, glabrous or glabrate. Basal leaves petiolate; blades elliptic-ovate, oblong, or subreniform, 20–50 × 10–40+ mm, bases subcordate, truncate, or cuneate, margins usually crenate-dentate to coarsely dentate-lacerate, seldom subentire. Cauline leaves gradually reduced (petiolate, resembling basals, sublyrate or dissected; distal sessile, subentire to pinnatifid). Heads 8–20+ in subumbelliform arrays. Peduncles ebracteate (or bractlets inconspicuous), glabrous or glabrate. Calyculi conspicuous (bractlets green, tips sometimes reddish). Phyllaries 13 or 21, green (tips sometimes reddish), 7–9 mm, glabrous. Ray florets 0 or 8–10; corolla laminae (deep yellow) 3–5 mm. Disc florets 60–70+; corolla tubes 2–3 mm, limbs 2.5–3.5 mm. Cypselae 1–2 mm, glabrous; pappi 3–4 mm. 2n = 46, 126, 176, 184.

Senecio indecorus Greene, Fl. Francisc., 470. 1897; S. burkei Greenman; S. idahoensis Rydberg; S. pauciflorus Pursh subsp. fallax Greenman

Packera indecora is a species of flowering plant in the aster family known by the common names elegant groundsel and rayless mountain ragwort. It is native to northern North America including most of Canada and sections of the northernmost United States. It grows in moist mountain habitat, such as streamsides and meadows.

It is a perennial herb producing a single stem or a cluster of 2 or 3 stems from a branching caudex and a taproot. The plant reaches heights of ten centimeters to one meter. The leaves have thin, oblong or oval blades a few centimeters long borne on long petioles. Smaller, more intricately divided leaves may occur farther up the stem.

The inflorescence is an umbel-shaped array of up to 20 or more flower heads, each lined with green- or red-tipped phyllaries. The head contains many disc florets and occasionally a tiny yellow ray floret, though these are usually absent.