Contains 5 accepted taxa overall.

Characteristics
Ulmus L.
ELM
The elms have been significantly impacted by the ascomycete Ophiostoma (Dutch elm disease) (Brasier & Buck 2001).
Classification
ROSALES
Ulmus
Citation
ULMUS Linnaeus, Sp. Pl. 225. 1753.
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TYPE: Ulmus campestris Linnaeus Lectotypified by Britton & A. Brown, Ill. Fl. N. U.S., ed. 2. 1: 626. 1913.
Species
Scientific Name Common Name Herbarium Specimens Status Photos
Ulmus alata WINGED ELM Native FACU (NWPL) FACW (DEP)
Ulmus americana AMERICAN ELM Native FAC (NWPL) T (WAP) FACW (DEP)
Ulmus crassifolia CEDAR ELM Native FAC (NWPL) FACW (DEP)
Ulmus parvifolia CHINESE ELM Not Native FACU (NWPL) FACW (DEP)
Ulmus rubra SLIPPERY ELM Native FAC (NWPL)
[Family identification key]
1.  Leaf blade mostly simply serrate; flowering late summer-fall
1.  Leaf blade mostly doubly serrate (the larger teeth with small teeth along the margin); flowering late summer-fall or winter-spring
2
2.  Stems sometimes corky-winged; petiole 0-3 mm long; leaf blades obtuse to acute, subtly acuminate at the tip; flowering late summer-fall or winter-spring
3
2.  Stems not corky-winged; petiole 3-10 mm long; leaf blades cuspidate-acuminate at the tip; flowering winter-spring
4
3.  Leaf blades usually smooth on the upper surface, mostly acute to acute-acuminate at the tip; samaras long-ciliate, 6-8 mm long; pedicel 2-7 mm long; calyx lobes 5; flowering Jan-Apr, before leafing out
3.  Leaf blades scabrous on the upper surface, mostly bluntly acute to obtuse at the tip; samaras ciliolate, 8-10 mm long; pedicel 7-10 mm long; calyx lobes 6-9; flowering Jul-Oct, among fully developed leaves
4.  Young stems glabrous to pubescent; buds glabrous to shortly pubescent; leaf blades smooth to lightly scabrous on the upper surface; pedicel 10-20 mm long; samaras ovate, 10-13 mm long, ciliate on the margin
4.  Young stems often densely pubescent; buds long-pubescent; leaf blades strongly scabrous on the upper surface; pedicel 1-2 mm long; samaras orbicular, 14-17 mm long, the margin not ciliate
Genus Synonyms
Synonym Full Citation Basionym Type
Microptelea Microptelea Spach, Ann. Sci. Nat., Bot., ser. 2. 15: 358. 1841. TYPE: Microptelea parvifolia (Jacquin) Spach (Ulmus parvifolia Jacquin)