Ulmus pumila
Ulmaceae
Asiatic elm, dwarf elm, Siberian elm
elm family
gray to brown, deeply furrowed with interlacing ridges.
smooth to deeply fissured or scaly and flaky;
sap watery.
not winged;
twigs gray-brown, pubescent.
dark brown, ovoid, glabrous;
scales light brown, shiny, glabrous to slightly pubescent.
blade narrowly elliptic to lanceolate, 2-6.5 × 2-3.5 cm, base generally not oblique, margins singly serrate, apex acute;
surfaces abaxially with some pubescence in axils of veins, adaxially glabrous;
lateral veins forking to 3 times per side.
blade: base often oblique, margins entire or serrate, crenate, or toothed;
venation pinnate to palmate-pinnate.
tightly clustered fascicles, 6-15-flowered, 0.5 cm, flowers and fruits not pendulous, sessile.
axillary, cymes, racemes, fascicles, or flowers solitary, arising from branchlets of previous season (e.g., Ulmus) or of current season (e.g., Celtis).
calyx shallowly lobed, lobes 4-5, glabrous;
stamens 4-8;
anthers brownish red;
stigmas green, lobes exserted.
bisexual or unisexual, staminate and pistillate on same [different] plants;
sepals persistent, (1-)5(-9), connate [distinct], imbricate or valvate;
petals absent;
stamens usually as many as calyx lobes, hypogynous, opposite calyx lobes, erect in bud;
filaments free or arising from calyx tube, distinct, curved or sigmoid in bud;
anthers 2-locular, dehiscence longitudinal;
pistils 1, 2(-3)-carpellate;
ovary 1(-2)-locular;
ovules 1 per locule, pendulous from apex of locule, anatropous or amphitropous;
styles (1-)2, distinct, receptive stigmatic area decurrent on distal inner margin of style branch.
fleshy drupes, samaras, or nutlike.
thickened, not inflated.
1;
arils absent;
endosperm absent to scanty, consisting of 1 layer of thick-walled cells;
embryo straight or curved.
brittle.
yellow-cream, orbiculate, 10-14 mm diam., broadly winged, glabrous, tip notched 1/3-1/2 its length.
= 28.
Ulmus pumila
Ulmaceae
Ulmus pumila probably occurs in Vermont and West Virginia, but it has not been documented for those states.
Planted for quick-growing windbreaks, Ulmus pumila has weak wood, and its branches break easily in mature trees. It is easily distinguished from other North American elms by its singly serrate leaf margins. Ulmus pumila is similar to U. parvifolia Jacquin with its small, singly serrate leaves. Ulmus parvifolia, however, has smooth bark that sheds from tan to orange, and it flowers and sets fruit in the fall.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Genera ca. 18, species ca. 150 (4 genera, 19 species in the flora).
Plants of this family are wind-pollinated (anemophilous).
Ulmaceae are frequently divided into two subfamilies, Ulmoideae and Celtoideae; they are sometimes separated into two families, Ulmaceae and Celtidaceae (I. A. Grudzinskaya 1965). These subfamilial or familial distinctions are supported by flavonoid chemistry (D. E. Giannasi and K. J. Niklas 1977; D. E. Giannasi 1978), pollen morphology (M. Zavada 1983), and some anatomic structures (E. M. Sweitzer 1971). Typically the Ulmoideae have flavonols, strictly pinnately veined leaves, and dry fruits; the Celtoideae have glycoflavones, pinnipalmately veined leaves, and drupaceous fruits. Some genera (e.g., Zelkova, with pinnately veined leaves and drupaceous fruits) are intermediate, and various authors place them in different subfamilies.
In this treatment Ulmus and Planera are considered part of the subfamily Ulmoideae; Celtis and Trema are in subfamily Celtoideae. Zelkova serrata is widely cultivated as an ornamental tree in North America, but it is not known to be naturalized in the flora. Chemical similarities between subfamilies include the presence of proanthocyanins with some tannins and scattered mucilaginous cells or canals. Additionally, members of the family share a strong tendency toward mineralization of the cell walls with calcium carbonate or silica and possess solitary or clustered crystals of calcium oxalate.
Ulmaceae include trees and shrubs of horticultural importance.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Leaf blade pinnately veined; fruits dry, nutlike or samaras. | → 2 |
1. Leaf blade palmately veined at base, pinnately veined over remainder of blade; fruits drupes. | → 3 |
2. Flowers bisexual; fruits samaras. | Ulmus |
2. Flowers normally unisexual, inflorescences usually with a few bisexual flowers; fruits nutlike. | Planera |
3. Leaf blade entire or serrate to ca. 3/4 length; flowers solitary or in few-flowered clusters; drupes 1. | Celtis |
3. Leaf blade crenate to serrate for entire length; flowers 12-20, in cymes. | Trema |
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OR, 
WA - Local Web sites: CalFlora, CalPhotos,
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WildflowerSearch
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- Local floras: CA, OR
- Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria
- WildflowerSearch
- iNaturalist (observations)
- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
