Alnus rhombifolia

Nuttall

N. Amer. Sylv. 1: 49. 1842.

Common names: White alder California alder
Endemic
Synonyms: Alnus rhombifolia var. bernardina Munz & I. M. Johnston
Treatment appears in FNA Volume 3.

Trees, to 35 m; trunks often several, crowns spreading, open. Bark light gray, smooth, becoming darker and breaking into scales in age; lenticels inconspicuous. Winter buds stipitate, ellipsoid to obovoid, 3–9 mm, apex rounded; stalks 3–5 mm; scales 2, equal, valvate, sometimes incompletely covering underlying leaves, moderately to heavily resin-coated. Leaf-blade narrowly elliptic to rhombic, rarely ovate, 4–9 × 2–5 cm, base cuneate to rounded, margins flat, finely serrate or serrulate, sometimes slightly lobed, without noticeably larger secondary teeth, apex acute or obtuse to rounded; surfaces abaxially sparsely pubescent to villous. Inflorescences formed season before flowering and exposed during winter; staminate catkins in 1 or more clusters of 3–7, 3–10 cm, stamens 2, or 4 with 2 reduced in size; pistillate catkins in 1 or more clusters of 2–6. Flowering before new growth in spring. Infructescences ovoid to nearly cylindric, 1–2.2 × 0.7–1 cm; peduncles 1–10 mm. Samaras broadly elliptic, wings narrower than body, irregular in shape, leathery.


Phenology: Flowering early spring.
Habitat: Open, rocky stream banks and adjacent (often rather dry) slopes
Elevation: 100–2400 m

Distribution

V3 456-distribution-map.gif

Calif., Idaho, Mont., Oreg., Wash.

Discussion

Alnus rhombifolia is the common alder throughout the dry Mediterranean climatic zone of coastal western United States. Mexican populations are not known, but because A. rhombifolia has been collected as far south as San Diego, California, it should be expected in adjacent Baja California.

Native Americans used various parts of Alnus rhombifolia medicinally for diarrhea, consumption, and burns, as a blood purifier, an emetic, and a wash for babies with skin diseases, and to facilitate childbirth (D. E. Moerman 1986).

Selected References

None.

Lower Taxa

None.

"persistent" is not a number.

... more about "Alnus rhombifolia"
Obtuse (?) +  and Rounded (?) +
John J. Furlow +
Nuttall +
tanniferous +  and furrowed +
darker +  and light gray +
exfoliating +
cuneate +  and rounded +
2 (?) +  and 3 (?) +
Ellipsoid (?) +  and Obovoid (?) +
0.3 cm3 mm <br />0.003 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
pistillate +  and staminate +
in relatively small racemose clusters +  and solitary +
solitary +, cluster +  and racemose +
erect +  and nearly pendulous +
proximal +  and lateral +
enclosed in buds +  and exposed +
ovoid +  and ellipsoid +
expanding +
3 cm30 mm <br />0.03 m <br /> (10 cm100 mm <br />0.1 m <br />) +
White alder +  and California alder +
multibracteate +
Calif. +, Idaho +, Mont. +, Oreg. +  and Wash. +
100–2400 m +
pistillate +  and staminate +
reduced +  and small +
small +  and large +
Open, rocky stream banks and adjacent (often rather dry) slopes +
1 cm10 mm <br />0.01 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
ovoid +  and nearly cylindric +
1 cm10 mm <br />0.01 m <br /> (4 cm40 mm <br />0.04 m <br />) +
0.7 cm7 mm <br />0.007 m <br /> (1 cm10 mm <br />0.01 m <br />) +
membranaceous +  and leathery +
4 cm40 mm <br />0.04 m <br /> (9 cm90 mm <br />0.09 m <br />) +
2 cm20 mm <br />0.02 m <br /> (5 cm50 mm <br />0.05 m <br />) +
3-ranked +  and nearly 2-ranked +
inconspicuous +
serrulate +  and serrate +
0.1 cm1 mm <br />0.001 m <br /> (1 cm10 mm <br />0.01 m <br />) +
not obvious +  and defined +
membranaceous +
Flowering early spring. +
2(-3)-carpellate +
N. Amer. Sylv. +
1-seeded +  and 2-winged +
crowded +  and imbricate +
resin-coated +
deciduous +  and persistent +
expanding +
thicker +  and thin +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
2 (?) +  and 4 (?) +
reduced +
nearly +  and distinct +
abaxially sparsely pubescent;villous +
Alnus rhombifolia var. bernardina +
Alnus rhombifolia +
species +
excurrent +  and deliquescent +
differentiated +  and uniform +
irregular +
leathery +
narrower +
tanniferous +
light +  and white +