Pseudognaphalium leucocephalum |
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white cudweed, white rabbit-tobacco |
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Habit | Biennials or short-lived perennials, 30–60 cm; taprooted. |
Stems | densely and persistently white-tomentose, usually with stipitate-glandular hairs protruding through tomentum. |
Leaf | blades (crowded, internodes mostly 1–3, sometimes to 10 mm) linear-lanceolate, 3–7 cm × 1–5(–6) mm, bases subclasping, not decurrent, margins strongly revolute, faces bicolor, abaxial densely white-tomentose, adaxial green, densely stipitate-glandular. |
Involucres | broadly campanulate, 5–6 mm. |
Pistillate florets | 66–85. |
Bisexual florets | (6–14, California)29–44. |
Phyllaries | in 5–7 series, bright white (opaque, dull), oblong to oblong-ovate, glabrous. |
Heads | in corymbiform arrays. |
Cypselae | ridged, smooth. |
2n | = 28. |
Pseudognaphalium leucocephalum |
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Phenology | Flowering (Jul–)Aug–Nov(–Dec). |
Habitat | Sandy or gravelly slopes, stream bottoms, arroyos, areas of oak-sycamore, oak-pine, to pine woodlands, commonly in riparian vegetation |
Elevation | 50–2100 m (200–6900 ft) |
Distribution |
AZ; CA; NM; Mexico (Baja California, Baja California Sur, Chihuahua, Durango, Sinaloa, Sonora)
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Discussion | Pseudognaphalium leucocephalum is similar to P. viscosum, which has shiny, hyaline, ovate-lanceolate phyllaries, 200–250 pistillate florets, (13–)16–29 bisexual florets, and papillate-roughened cypselae. Some plants of P. leucocephalum also appear to approach P. biolettii in general appearance, and it is possible that some of them may represent hybrids. Plants of P. biolettii differ from P. leucocephalum in their typically eglandular stems, broader, basally ampliate, clasping, more widely spaced, and less densely glandular leaves, and thinner, shiny phyllaries. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 19, p. 423. |
Parent taxa | Asteraceae > tribe Gnaphalieae > Pseudognaphalium |
Sibling taxa | |
Synonyms | Gnaphalium leucocephalum |
Name authority | (A. Gray) Anderberg: Opera Bot. 104: 147. (1991) |
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