A Preliminary Key to Pycnosorus (Asteraceae, Gnaphalieae)
First published online 2013
The genus Pycnosorus contains six species and is endemic to Australia. This key is based entirely on information from publications by J.Everett & A.N.L.Doust (Telopea 5: 39–43 (1992); Flora of New South Wales 3: 260–262 (1992)), and not on original research. Its major advantages are that it focuses on more easily accessible characters and that it is the first key to include all currently accepted species of the genus. The species names link to the relevant entry in the Australian Plant Name Index (APNI).
Phyllaries and pappus white or translucent
You are most likely dealing with a Craspedia or Calocephalus, perhaps even with Angianthus or another genus altogether.
Phyllaries yellow, pappus yellow at least at tip
Leaves with glandular and septate hairs, with or without additional woolly hairs; glomerule often branched basally
Leaves with woolly hairs and perhaps a few glands apically, without septate hairs; glomerule never branched
Leaves linear-ovate to narrowly spathulate, 20–60 x 2–6 mm, often with woolly hairs on margins and abaxial surface; bracts subtending partial heads scarious only at tip; flowers golden-yellow
Leaves oblong to oblanceolate, 30–70 x 2–10 mm, with glandular and septate hairs only; bracts subtending partial heads with broad yellow scarious margins; flowers lemon-yellow
Plants only to 25 cm tall; glomerules cylindrical, 8–38 x 5–11 mm; restricted to a small area in north-easternmost South Australia and adjacent Queensland (Birdsville etc.)
Plants often taller; glomerules globose or ovoid, about as wide as long; more widespread species
Plants only to 35 cm tall; leaves 10–50 mm long; glomerules 4–12 mm diam.; bracts subtending partial heads with wide scarious margins; restricted to southern Queensland and NSW
Plants often taller; leaves 17–300 mm long; glomerules 8–35 mm diam.; bracts subtending partial heads with narrow scarious margins (<1/2 as wide as stereome); widespread species
Plants to 120 cm tall; leaves 100–300 x 9–20 mm, with 3–8 veins, entirely woolly; glomerules globose, 8–35 mm diam.
Plants to 60 cm tall; leaves 17–100 x 2–7 mm, with one vein, woolly on margins and on the vein on the abaxial side; glomerules ovoid, 8–15 x 9–20 mm