Alnus maritima

(Marshall) Muhlenburg ex Nuttall

N. Amer. Sylv. 1: 50. 1842.

Common names: Seaside alder brook alder
EndemicIllustrated
Basionym: Betula-alnus maritima Marshall Arbust. Amer., 20. 1785
Treatment appears in FNA Volume 3.

Shrubs or trees, to 10 m; crowns narrow. Bark light gray, smooth; lenticels small, inconspicuous. Winter buds stipitate, ovoid to ellipsoid, 2.5–5 mm, apex rounded; stalks 1–3 mm; scales 2–3, subequal, often poorly developed, heavily resin-coated. Leaf-blade narrowly elliptic, oblong, or narrowly obovate, 4.5–9 × 2–5 cm, leathery, base acute to cuneate, margins flat, teeth low, single, relatively distant, apex acute, obtuse, or rounded; surfaces abaxially mostly glabrous, resin-coated when young. Inflorescences: catkins formed during same season as flowering; staminate catkins in 1 terminal cluster of 2–4, 2–6 cm; pistillate catkins solitary in leaf-axils proximal to staminate catkins. Flowering in late summer or early fall. Infructescences ovoid, 1.2–2.8 × 1.2–2.2 cm; peduncles 5–10 mm. Samaras elliptic, wings reduced to narrow, leathery ridges. 2n = 28.


Phenology: Flowering late summer–early fall.
Habitat: Along edges of ponds and small streams, often in standing water
Elevation: 0–100 m

Discussion

Alnus maritima consists of widely disjunct populations in Delaware, Maryland, and southern Oklahoma. The populations probably represent remnants of Pleistocene and post-Pleistocene distributions and migrations. It is our only member of the predominantly Asian fall-blooming Alnus subg. Clethropsis.

Selected References

None.

Lower Taxa

None.

"persistent" is not a number.

... more about "Alnus maritima"
Rounded (?) +, Obtuse (?) +  and Acute (?) +
John J. Furlow +
(Marshall) Muhlenburg ex Nuttall +
tanniferous +  and furrowed +
light gray +
exfoliating +
acute +  and cuneate +
Betula-alnus maritima +
2 (?) +  and 3 (?) +
Ovoid (?) +  and Ellipsoid (?) +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
pistillate +  and staminate +
solitary +, cluster +  and racemose +
erect +  and nearly pendulous +
proximal +  and lateral +
enclosed in buds +  and exposed +
ovoid +  and ellipsoid +
expanding +
2 cm20 mm <br />0.02 m <br /> (6 cm60 mm <br />0.06 m <br />) +
Seaside alder +  and brook alder +
multibracteate +
Del. +, Md. +  and Okla. +
0–100 m +
pistillate +  and staminate +
reduced +  and small +
small +  and large +
Along edges of ponds and small streams, often in standing water +
1.2 cm12 mm <br />0.012 m <br /> (2.8 cm28 mm <br />0.028 m <br />) +
1 cm10 mm <br />0.01 m <br /> (4 cm40 mm <br />0.04 m <br />) +
1.2 cm12 mm <br />0.012 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
membranaceous +  and leathery +
4.5 cm45 mm <br />0.045 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 +
entire +, serrulate +  and serrate +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
not obvious +  and defined +
membranaceous +
Flowering late summer–early fall. +
2(-3)-carpellate +
N. Amer. Sylv. +
1-seeded +  and 2-winged +
crowded +  and imbricate +
resin-coated +
deciduous +  and persistent +
2 +  and 3 +
subequal +
expanding +
thicker +  and thin +
Endemic +  and Illustrated +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
nearly +  and distinct +
resin-coated +
Alnus maritima +
species +
excurrent +  and deliquescent +
differentiated +  and uniform +
tree +  and shrub +
reduced;narrow +
tanniferous +
light +  and white +