4. Pseudognaphalium microcephalum (Nuttall) Anderberg, Opera Bot. 104: 147. 1991.
San Diego rabbit-tobacco
Gnaphalium microcephalum Nuttall, Trans. Amer. Philos. Soc., n. s. 7: 404. 1841; G. albidum I. M. Johnston; G. canescens de Candolle subsp. microcephalum (Nuttall) Stebbins & D. J. Keil; Pseudognaphalium canescens (de Candolle) Anderberg subsp. microcephalum (Nuttall) Kartesz
Perennials, (30–)50–100 cm; taprooted. Stems persistently grayish tomentose, not glandular, (3–5 mm diam. near bases). Leaf blades narrowly oblanceolate, 2–5(–8) cm × 5–10(–18) mm (gradually smaller distally, becoming lanceolate), bases not clasping, not decurrent, margins flat, faces weakly bicolor, tomentose (adaxial less densely), not glandular. Heads in loose, corymbiform arrays. Involucres turbinate-campanulate, 5–6 mm. Phyllaries in 4–5 series, white (opaque, dull), ovate to oblong-ovate (inner narrower, all usually with filiform but definitely thickened keel and slight apiculum), tomentose (at least bases). Pistillate florets 29–49. Bisexual florets 5–9. Cypselae ridged, smooth to weakly papillate-roughened. 2n = 28.
Flowering (Apr–)Jun–Aug(–Nov). Grassy hillsides, gravelly canyon bottoms, chaparral, coastal sage scrub; 50–900(–1800) m; Calif.; Mexico (Baja California).
Pseudognaphalium microcephalum is characterized by stems commonly stiffly erect and slightly zigzag distally, relatively thick (3–5 mm diam. near bases), and closely grayish tomentose, leaves oblanceolate, sessile, sometimes clasping, not decurrent, and weakly bicolor, and heads usually in open, corymbiform arrays.