Opera Bot. 104: 148. 1991
Annuals (viscid and unpleasantly aromatic), 30–100 cm; taprooted. Stems persistently white-tomentose and stipitate-glandular. Leaf blades (crowded, internodes mostly 1–3, sometimes to 10, mm) linear-lanceolate, (2–)4–8 cm × 3–10 mm, bases not clasping, usually (at least the proximal) decurrent 3–10 mm, margins strongly revolute to revolute-undulate, faces bicolor, abaxial densely white-tomentose, adaxial densely stipitate-glandular. Heads in corymbiform arrays. Involucres campanulate, 5–6 mm. Phyllaries in 5–6 series, tawny-silvery to silvery white (hyaline, shiny), ovate-lanceolate (not keeled or thickened along midribs, not apiculate), glabrous. Pistillate florets 200–250. Bisexual florets (13–)16–29. Cypselae not ridged, papillate-roughened. 2n = 28.
Phenology: Flowering Jul–Sep.
Habitat: Rocky open sites, roadsides
Elevation: 1400–1800 m
Tex., Mexico, Central America.
Reports of Pseudognaphalium viscosum from the flora for states other than Texas are based on plants of P. macounii. Pseudognaphalium viscosum is similar to P. leucocephalum, which has broader and white-opaque phyllaries, longer bisexual corollas, and smooth cypselae.