Baccharis pteronioides

de Candolle in A. P. de Candolle and A. L. P. P. de Candolle

in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 5: 410. 1836.

Common names: Yerba de pasmo
Synonyms: Baccharis ramulosa (de Candolle) A. Gray
Treatment appears in FNA Volume 20. Treatment on page 31. Mentioned on page 24, 25.

Shrubs, 30–100 cm (diffusely and evenly branched with thick woody crowns). Stems erect, terete, brittle, slightly striate, scabrous, stipitate-glandular, papillose-roughened. Leaves cauline (proximal withering before flowering, distal crowded in gascicles); sessile; blades linear to lanceolate or spatulate, 5–25 × 1–6 mm (stiff, coriaceous to fleshy), bases attenuate, margins sharply serrate (teeth 1–5 pairs, distal leaves often entire), faces glabrous, gland-dotted, resinous. Heads (10–20+ on densely leafy lateral branchlets) in spreading racemiform arrays. Involucres campanulate; staminate 4–5 mm, pistillate 5–6 (–7) mm. Phyllaries ovate to lanceolate, 1–5 mm, margins scarious, medians green, apices acute to acuminate, glabrous. Staminate florets 15–20; corollas 4–5 mm. Pistillate florets 15–20; corollas 4–5 mm. Cypselae 1.8–3 mm, 8–10-nerved, minutely papillose-glandular; pappi 8–10 mm (bristles rigid).


Phenology: Flowering Apr–Jun.
Habitat: Dry canyons, roadsides, open oak woodlands, grasslands
Elevation: 300–2000 m

Distribution

V20-25-distribution-map.gif

Ariz., N.Mex., Tex., Mexico

Discussion

Baccharis pteronioides is characterized by its shrubby stiff habit, rough gray bark, branches that are evenly spaced and often at 45° angles, fascicles of narrow sessile leaves, and heads in racemiform arrays on short leafy branches. The Mexican common name yerba de pasmo refers to an infusion of the leaves used to treat chills (pasmo) and sores; the plants are also said to be poisonous to cattle and sheep.

Selected References

None.

Lower Taxa

None.
... more about "Baccharis pteronioides"
not tailed +, rounded +  and obtuse +
distinct +
subequal +
scarious +
usually triangular +  and linear +
usually deltate +  and lanceolate +
indeterminate +  and determinate +
Scott D. Sundberg† +  and David J. Bogler +
de Candolle in A. P. de Candolle and A. L. P. P. de Candolle +
attenuate +
3-nerved +  and 1-nerved +
0.5 cm5 mm <br />0.005 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
linear;lanceolate or spatulate +
1mm;6mm +
rugulose +  and muricate +
barbellulate +  and barbellate +
Yerba de pasmo +
not 2-lipped +  and actinomorphic +
whitish +, white +  and pale-yellow +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
beaked +, 2-ribbed +  and 5-ribbed +
hispid +  and glabrous +
compressed +, obovoid +  and cylindric +
fertile +  and bisexual +
Ariz. +, N.Mex. +, Tex. +  and Mexico +
300–2000 m +
resinous +
gland-dotted +
pistillate +  and staminate +
winged +  and beaked +
dispersed +
Dry canyons, roadsides, open oak woodlands, grasslands +
racemiform +, corymbiform +  and paniculiform +
indeterminate +
heterogamous +  and homogamous +
each +  and sessile +
pistillate +  and staminate +
0.6 cm6 mm <br />0.006 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
campanulate +
0.5 cm5 mm <br />0.005 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
spreading-reflexed;spreading-reflexed +
less deltate +  and lanceovate +
hispid +  and glabrous +
2-carpellate +
brownish +, whitish +  and tawny +
persistent +
25 +  and 50 +
0.8 cm8 mm <br />0.008 m <br /> (1 cm10 mm <br />0.01 m <br />) +
Flowering Apr–Jun. +
ovate +  and lanceolate +
0.1 cm1 mm <br />0.001 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. +
styliferous +, neuter +  and pistillate +
bearing subulate enations +, hairy +  and bristly +
conic;tholiform;conic;tholiform;flat +
exalbuminous +
1 (?) +  and 20 (?) +
resinous +
papillose-roughened +
appendaged +  and truncate +
papillate +  and smooth +
Baccharis ramulosa +
Baccharis pteronioides +
Baccharis +
species +