Alnus oblongifolia
Alnus serrulata
aliso (Mexico), Arizona alder, New Mexican alder, oblong leaf alder
hazel alder, smooth alder
dark gray, smooth, becoming blackish and breaking into shallow vertical plates in age;
lenticels inconspicuous.
blade narrowly ovate or lanceolate to narrowly elliptic, 5–9 × 3–6 cm, leathery, base narrowly to broadly cuneate or narrowly rounded, margins flat, sharply and coarsely doubly serrate, rarely evenly and densely short-serrate, major teeth sharp, acuminate, secondary teeth distinctly larger, apex long to short-acuminate, rarely acute;
surfaces abaxially glabrous to sparsely pubescent or infrequently villous, moderately resin-coated.
blade broadly elliptic to obovate, 5–14 × 3.5–8 cm, leathery, base broadly to narrowly cuneate, margins flat, serrulate, without noticeably larger secondary teeth, apex obtuse to rounded;
surfaces abaxially glabrous to moderately villous, slightly to moderately resin-coated.
formed season before flowering and exposed during winter; staminate catkins in 1 or more clusters of 3–6, 3.5–10 cm; pistillate catkins in 1 or more clusters of 2–7.
formed season before flowering and exposed during winter; staminate catkins in 1 or more clusters of 2–5, 3–8.5 cm, stamens 4; pistillate catkins in 1 or more clusters of 3–5.
ovoid, ellipsoid, or nearly cylindric, 1–2.5 × 0.8–1.5 cm;
peduncles 5–10 mm.
ovoid-ellipsoid, 1–2.2 × 0.6–1.2 cm;
peduncles 1–3(–5) mm.
buds stipitate, ovoid, 4–8 mm, apex rounded;
stalks 1.5–4 mm;
scales 2, equal, valvate, sometimes incompletely covering underlying leaves, moderately resin-coated.
buds stipitate, ellipsoid to obovoid, 3–6 mm, apex mostly rounded;
stalks 2–4 mm;
scales 2, equal, valvate, moderately to heavily resin-coated.
before new growth in spring.
before new growth in spring.
elliptic to obovate, wings narrower than body, irregular in shape, leathery.
obovate, wings narrower than body, irregularly elliptic or obovate, leathery.
= 28.
Alnus oblongifolia
Alnus serrulata
Alnus oblongifolia is closely related to the Mexican and Central American A. acuminata, with which it has sometimes been confused. It is found only in scattered populations in the temperate deciduous forest vegetation zone of high mountains in the arid Southwest.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Primarily an Atlantic coastal species, Alnus serrulata also grows along the St. Lawrence river system and the lower Great Lakes westward to the dunes of southern Lake Michigan, and across the southern states to the Gulf Coast and east Texas. Alnus serrulata was erroneously called A. rugosa in a number of earlier floristic works (J. K. Small 1903, 1933; N. L. Britton and A. Brown 1896, 1913; and B. L. Robinson and M. L. Fernald 1908), and the mistake was perpetuated in both editions of Flora Europaea (T. G. Tutin et al. 1964–1980, vol. 1; 1993+, vol. 1).
Alnus incana subsp. rugosa hybridizes with A. serrulata (= Alnus serrulata var. subelliptica Fernald). Extensive hybrid swarms occur where the ranges of these species overlap, including the area along the St. Lawrence River and the southern edge of the Great Lakes (F. L. Steele 1961). R. H. Woodworth's conclusion (1929, 1930) that apomixis occurs in A. serrulata resulted from his use of material selected from a hybrid swarm. The remainder of the species appears to reproduce normally. The two species and their hybrids are usually easily distinguished by leaf shape and margin characters.
Various preparations of Alnus serrulata were used medicinally by Native Americans to alleviate pain of childbirth, as a blood tonic, an emetic and purgative, for coughs and fevers, to stimulate kidneys, to bathe hives or piles, for eye troubles, indigestion, biliousness, jaundice, heart trouble, mouth soreness in babies, and toothaches, to lower blood pressure, and to clear milky urine (D. E. Moerman 1986).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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