1. Pseudognaphalium helleri (Britton) Anderb. (rabbit tobacco)
Pl. 294 g, h;
strongly aromatic when bruised or crushed. Stems 25–75 cm long,
sometimes somewhat woolly when young, but not appearing woolly below the
inflorescence at maturity, instead moderately to densely glandular-hairy, the
stalked glands variously 0.2–1.0 mm long on the same stem. Leaves
1–9 cm long, linear to narrowly lanceolate or narrowly
oblong-lanceolate, the upper surface with moderate to dense, minute, stalked
glands. August (July–November elsewhere).
introduced, known from a single historical collection from St. Louis County (southeastern U.S. west to Oklahoma and Texas). Habitat unknown.
(1963) overlooked the single specimen from Missouri, and it remained hidden in
the Missouri Botanical Garden herbarium under the name Gnaphalium
polycephalum Michx. until its rediscovery in 2000 by Guy Nesom of the
Botanical Research Institute of Texas. The closest known native populations in
central Arkansas, northern Mississippi, and eastern Kentucky and Tennessee are not particularly close to the Missouri record from Allenton. Although it is
plausible that the historical St. Louis County collection represents a native
occurrence, it seems more likely that the plant originated from a disturbed
habitat such as a railroad embankment.