Pseudognaphalium microcephalum

(Nuttall) Anderberg

Opera Bot. 104: 147. 1991.

Common names: San Diego rabbit-tobacco
Basionym: Gnaphalium microcephalum Nuttall Trans. Amer. Philos. Soc., n. s. 7: 404. 1841
Synonyms: Gnaphalium albidum I. M. Johnston Gnaphalium canescens subsp. microcephalum (Nuttall) Stebbins & D. J. Keil Pseudognaphalium canescens subsp. microcephalum (Nuttall) Kartesz
Treatment appears in FNA Volume 19. Treatment on page 419. Mentioned on page 417.

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.


Phenology: Flowering (Apr–)Jun–Aug(–Nov).
Habitat: Grassy hillsides, gravelly canyon bottoms, chaparral, coastal sage scrub
Elevation: 50–900(–1800) m

Distribution

V19-683-distribution-map.gif

Calif., Mexico (Baja California)

Discussion

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.

Selected References

None.

Lower Taxa

None.
white +  and gray +
tomentose +  and velutinous +
grayish;greenish +
arachnose +, glabrescent +  and glabrous +
scarious +
mostly ovate +  and lanceovate or linear +
indeterminate +  and determinate +
Guy L. Nesom +
(Nuttall) Anderberg +
not decurrent +
Gnaphalium microcephalum +
compound +  and simple +
mostly narrowly lanceolate;oblanceolate +
5-ribbed +, 3-ribbed +  and 2-ribbed +
muriculate +, papillate +  and smooth +
San Diego rabbit-tobacco +
actinomorphic +
smooth +  and weakly papillate-roughened +
Calif. +  and Mexico (Baja California) +
50–900(–1800) m +
papillate-roughened +
winged +  and beaked +
dispersed +
Grassy hillsides, gravelly canyon bottoms, chaparral, coastal sage scrub +
singly +  and aggregated +
indeterminate +
homogamous +  and heterogamous +
each +  and sessile +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
turbinate-campanulate +
0.5 cm5 mm <br />0.005 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
5 cm50 mm <br />0.05 m <br /> (8 cm80 mm <br />0.08 m <br />) +
1 cm10 mm <br />0.01 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
2 cm20 mm <br />0.02 m <br /> (5 cm50 mm <br />0.05 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
cauline +  and basal +
rarely lanceovate +  and lanceolate +
2-carpellate +
persistent +
Flowering (Apr–)Jun–Aug(–Nov). +
bearing subulate enations +, hairy +  and bristly +
conic;more or less columnar +
4 +  and 6 +
exalbuminous +
decumbent +  and procumbent +
appendaged +  and truncate +
papillate +
Gnaphalium albidum +, Gnaphalium canescens subsp. microcephalum +  and Pseudognaphalium canescens subsp. microcephalum +
Pseudognaphalium microcephalum +
Pseudognaphalium +
species +
30 cm300 mm <br />0.3 m <br /> (50 cm500 mm <br />0.5 m <br />) +
50 cm500 mm <br />0.5 m <br /> (100 cm1,000 mm <br />1 m <br />) +
shrub +  and subshrub +