Contains 10 accepted taxa overall.

Characteristics
Crataegus L.
HAWTHORN
Classification
ROSALES
Crataegus
Citation
CRATAEGUS Linnaeus, Sp. Pl. 475. 1753, nom. cons. vs. Mespilus Linnaeus 1753.
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TYPE: Crataegus oxyacantha Linnaeus, nom. rej. Lectotypified by Britton & A. Brown, Ill. Fl. N. U.S., ed. 2. 2: 294. 1913; M. L. Green, Prop. Brit. Bot. 158. 1929.
Distribution Map Present

This species have been reported in the counties highlighted.

Species
Scientific Name Common Name Herbarium Specimens Status Photos
Crataegus aestivalis MAY HAW; MAY HAWTHORN Native OBL (NWPL) OBL (DEP)
Crataegus crus-galli COCKSPUR HAWTHORN Native FAC (NWPL)
Crataegus flava YELLOWLEAF HAWTHORN; BEAUTIFUL HAWTHORN; SARGENT'S HAWTHORN Native FAC (NWPL)
Crataegus marshallii PARSLEY HAWTHORN Native FAC (NWPL) FACW (DEP)
Crataegus michauxii MICHAUX'S HAWTHORN Native
Crataegus opaca RIVERFLAT HAWTHORN; WESTERN MAYHAW Native OBL (NWPL)
Crataegus phaenopyrum WASHINGTON HAWTHORN Native Rare-State FAC (NWPL)
Crataegus spathulata LITTLEHIP HAWTHORN Native FAC (NWPL)
Crataegus uniflora DWARF HAWTHORN Native
Crataegus viridis GREEN HAWTHORN Native FACW (NWPL) FACW (DEP)
Identification Key
1.  Proximal vein axils of leaf blade undersides cavernous, forming pubescent (rarely glabrate) pockets (domatia)
2
1.  Proximal vein axils of leaf blades undersides flush with the rest of the blade, glabrous (midrib and secondary veins sometimes sparsely pilose)
8
2.  Leaf blades mostly dentate to serrate, the teeth generally triangular, the blades mostly (3)4-7 cm long
3
2.  Leaf blades mostly subentire to crenate, the teeth generally rounded, the blades mostly 1-5 cm long
5
3.  Leaf blade underside glabrescent except for pubescence around domatia; pedicels 5-15 mm long; fruits 5-8 mm wide
3.  Leaf blade underside midribs and veins densely rufous-pubescent; pedicels 0-3 mm long; fruits (8)12-15 mm wide
4
4.  Leaf blade elliptic to broadly elliptic, lateral veins 5-9 per side; pedicels glabrate; fruits 12-15 mm wide
4.  Leaf blade broadly elliptic to obovate; lateral veins 3-5 per side; pedicels rufous-pubescent; fruits 10-12 mm wide
5.  Leaf blade upperside glabrous to scabridulous, underside midribs and veins sparsely strigose, sparsely pubescent, to glabrous except for pale pubescence around domatia; leaf blade and bracteole marginal glands obscure; fruits 8-20 mm wide; of hydric to mesic-hydric areas
5.  Leaf blade upperside and underside sparsely strigose to denseely pubescent; fruits (5)6-12(15) mm wide; of xeric to mesic-xeric areas
6
6.  Leaf blade margins without glands or these obscure
6.  Leaf blade and bracteole marginal glands usually prominent
7
7.  Branches weeping or pendent; leaf blade narrowly spatulate (sometimes broader on young shoots)
7.  Brnaches spreading, not pendent; leaf blade broadly spatulate to obovate
8.  Leaf blades broadest near the base
9
8.  Leaf blades broadest above the middle
11
9.  Leaf blades pinnately dissected-lobed, sinuses nearly reaching midrib
9.  Leaf blades shallowly lobed, sinus less than halfway to midrib
10
10.  Leaf blades with 2 lateral lobes, the lobe tips acuminate; ovary 4-5 mm wide, fruits 8-10 mm wide
10.  Leaf blades weakly lobed, the lobe tips acute; ovary 2-3 mm wide, fruits 4-5 mm wide
11.  Pedicels 1-3 mm long; sepals often coarsely dentate with teeth >0.5 mm long
11.  Pedicels (4)8-25 mm long; sepals entire to weakly dentate with teeth <0.5 mm long
12
12.  Pedicel pubescent; sepals narrowly acute, 3-4 mm long; fruit >4 mm wide
12.  Pedicel glabrous; sepals deltoid, 1-2 mm long; fruit 3-4 mm wide
Genus Synonyms
Synonym Full Citation Basionym Type
Anthomeles Anthomeles M. Roemer, Fam. Nat. Syn. Monogr. 3: 102, 140. 1847. TYPE: Non designatus.
Azarolus Azarolus Borkhausen, Theoret. Handb. Forstbot. 2: 1224. 1803. TYPE: Non designatus.
Halmia Halmia Medikus ex M. Roemer, Fam. Nat. Syn. Monogr. 3: 101, 134. 1847. TYPE: Non designatus.
Oxyacantha Oxyacantha Medikus, Philos. Bot. 1: 150, 154, 155. 1789. TYPE: Non designatus.
Phaenopyrum Phaenopyrum M. Roemer, Fam. Nat. Syn. Monogr. 3: 103, 152. 1847. TYPE: Non designatus.
Phalacros Phalacros Wenzig, Linnaea 38: 164. 1874. TYPE: Phalacros cordata (Miller) Wenzig (Mespilus cordata Miller)
Xeromalon Xeromalon Rafinesque, New Fl. 3: 11. 1838. TYPE: Xeromalon obovatum Rafinesque