Flora of the Southeastern United States
2022 Edition

Colors

Data mode

Key to Crataegus, Key C: hawthorns with leaf blades widest at midpoint or beyond midpoint; blade bases acute or cuneate;
leaves eglandular, or if glandular then twigs and branchlets not geniculate

1 Leaves abaxially canescent, margins mostly entire; fruit calyx open, exposing pyrenes
1 Leaves abaxially pubescent, villous or glabrous, margins toothed; fruit calyx not fully open.
..2 Leaves spatulate or oblanceolate, < 13 mm wide; fruit < 6 mm diameter; pyrenes about 3 mm long
..2 Leaves variously shaped but most > 13 mm wide; fruit > 6 mm; pyrenes 4 mm long or more.
....3 Leaves abaxially with dense hair tufts in proximal main vein axils, especially in spring; [plants typically of wet or floodplain habitats].
......4 Inflorescence simple, 1-5-flowered; fruit 10-15 mm diameter, lustrous red, mature in late spring.
........5 Leaf blades mostly 5-7 cm long, elliptic, margin wavy or with uneven, blunt teeth
........5 Leaf blades usually < 5 cm long, most obovate, margin finely toothed.
..........6 Leaf adaxial surface usually glossy; whitish hair tufts in main vein axils abaxially
..........6 Leaf adaxial surface matte; reddish hair tufts in main vein axils abaxially
......4 Inflorescence compound, 5-20-flowered; fruit 5-15 mm diameter, dull red or orange-red, mature in autumn.
............7 Petiole 5-10 mm long; terminal shoot leaves < 25 mm broad
............7 Petiole > 10 mm long; terminal shoot leaves > 25 mm broad; [Virides series and hybrids].
..............8 Leaves glabrous, except for hair tufts.
................9 Leaves mostly ovate; terminal shoot leaves suborbicular, unlobed or barely lobed; bases rounded
................9 Leaves predominately lanceolate, elliptical, rhomboid or obovate; terminal shoot leaves often ovate; bases usually cuneate.
..................10 Leaves frequently lanceolate
..................10 Leaves rarely lanceolate, mostly elliptical or rhomboid.
....................11 Leaf serrations small or crenate; terminal shoot leaves often incised on each side nearly to midrib
....................11 Leaf serrations acute; terminal shoot leaves moderately lobed
..............8 Leaves and/or inflorescences hairy, at least in spring.
......................12 Terminal shoot leaves mostly ovate or rhomboid
........................13 Inflorescence densely pubescent; bracteoles thin, linear, caducous; leaves finely toothed
........................13 Inflorescence villous; bracteoles firm, persist through anthesis; leaves coarsely toothed
......................12 Terminal shoot leaves orbicular, elliptical or obovate
..........................14 Terminal shoot leaves orbicular, unlobed; young leaves white-tomentose; inflorescence glabrate
..........................14 Terminal leaves elliptical or obovate, prominently toothed; young leaves and inflorescence pubescent
....3 Leaves glabrous or with hairs scattered, not in tufts; [plants typically of upland habitats].
............................15 Pyrenes channeled or pitted on inner sides.
..............................16 Leaves persistently pubescent, at least on petiole or main veins abaxially.
................................17 Sepals glandular-serrate or subentire; inflorescence > 12-flowered
................................17 Sepals often deeply glandular-serrate or glandular-pectinate; inflorescence < 10-flowered
..................................18 Leaves sharply toothed and lobed
..................................18 Leaves dentate-serrate, usually unlobed
..............................16 Leaves glabrous or glabrate abaxially after maturity
....................................19 Leaves scabrate adaxially when young; stamens 7-10
....................................19 Leaves not scabrate; stamens 5-20.
......................................20 Pyrenes with a shallow groove or depression; leaf venation vaguely reticulate, barely impressed adaxially
......................................20 Pyrenes deeply grooved or pitted; leaf venation distinctly reticulate and impressed adaxially.
........................................21 Stamens 5-10 per flower; anthers 1-2 mm long
........................................21 Stamens 15-20 per flower; anthers < 1 mm long.
..........................................22 Leaf blades often narrowly obovate or broadly elliptic; fruit 6-8 mm in diameter
..........................................22 Leaf blades broadly obovate, rhombic or suborbicular; fruit 7-12 mm in diameter
............................15 Pyrenes plane on inner sides.
............................................23 Sepals foliaceous, equaling or exceeding petal length in flower and persistent on fruit; flowers usually 1-5 per inflorescence.
..............................................24 Terminal shoot leaves broadly elliptic or ovate, often shallowly lobed
..............................................24 Terminal shoot leaves mostly elliptic or obovate, unlobed
............................................23 Sepals not foliaceous, shorter than petals; flowers 5 or more per inflorescence
................................................25 Thorns short (< 2 cm), or spinose spur shoots present; main lateral leaf veins run to sinuses and lobe tips in lobed leaves.
..................................................26 Fruit black or blue; styles and pyrenes 3-5; most leaves elliptical; [native]
..................................................26 Fruit red; styles and pyrenes 2; most leaves rhombic or obovate; [exotic]
................................................25 Thorns usually > 2 cm long; main lateral leaf veins lead only to lobe tips in lobed leaves.
....................................................27 Petioles distinctly glandular, usually with 3 or more glands persistent.
......................................................28 Stamens 5-10 (-15) per flower.
........................................................29 Fruit flesh usually hard or dense; calyx collar elevated on fruit; leaves moderately lobed on terminal shoots.
..........................................................30 Anthers white or yellow
..........................................................30 Anthers pink or purplish.
............................................................31 Sepals deeply glandular-serrate; anthers pink
............................................................31 Sepals finely glandular-serrate; anthers purplish
........................................................29 Fruit flesh dense or soft; calyx collar sessile or nearly so on fruit; leaves shallowly lobed or unlobed on terminal shoots.
..............................................................32 Terminal shoot leaves suborbicular and 6-8 cm wide; [rare AL endemic]
..............................................................32 Terminal shoot leaves ovate or obovate, < 6 cm wide; [uncommon but widespread]
................................................................33 Leaf blades often obovate, 5-8 cm long
................................................................33 Leaf blades broadly elliptic or oval, most 4-6 cm long.
..................................................................34 Leaves usually shallowly but sharply lobed; anthers purplish; [AL, GA, SC]
..................................................................34 Leaves bluntly lobed or unlobed; anthers whitish or pink; [OK, AR, OK]
......................................................28 Stamens usually 20 per flower (often 30 or more in C. triflora).
....................................................................35 Leaves pubescent, at least abaxially; anthers white or yellowish.
......................................................................36 Sepals remotely glandular-serrate; petiolar glands sessile; fruit usually 8-12 mm diameter
......................................................................36 Sepals deeply glandular-serrate; petiolar glands stalked; fruit usually > 12 mm diameter.
........................................................................37 Leaves thin; inflorescence simple, 3-5-flowered; stamens usually 30 or more
........................................................................37 Leaves firm; inflorescence compound, > 5-flowered; stamens 20.
..........................................................................38 Terminal shoot leaves 4-5 cm wide, unlobed; sepals usually erect on fruit
..........................................................................38 Terminal shoot leaves 5-8 cm wide, with lobelike points; sepals patent in fruit
....................................................................35 Leaves glabrous; anthers pink to purplish, rarely white.
............................................................................39 Calyx collar sessile on fruit; fruit flesh soft and succulent at maturity.
..............................................................................40 Leaves mostly unlobed; inflorescence scabrous-pubescent; petiolar glands stalked
..............................................................................40 Leaves acutely lobed; inflorescence glabrate; petiolar glands sessile
............................................................................39 Calyx collar often elevated on fruit; fruit flesh usually dense or dry; [Pulcherrimae series].
................................................................................41 Terminal shoot leaves shallowly lobed or unlobed, apex obtuse, margins crenate-serrate
................................................................................41 Terminal shoot leaves shallowly to moderately lobed, apex usually acute, margins serrate.
..................................................................................42 Leaf margins often taper in a straight line from midpoint to apex
..................................................................................42 Leaf margins usually convex or bowed from midpoint to apex.
....................................................................................43 Petioles of smaller leaves winged 1/3 or less of length; leaf lobes convex-sided
....................................................................................43 Petioles of smaller leaves winged 1/2 length; leaf lobes straight on inner/distal side.
......................................................................................44 Leaf blades mostly 4-6 cm long, serrations obtuse; fruit ellipsoid or oval, pale yellow
......................................................................................44 Leaf blades often 5-8 cm long, serrations acute; fruit subglobose, red or yellowish
....................................................27 Petioles eglandular, or occasionally with 1 or 2 glands deciduous or obscure after spring. xx
........................................................................................45 Petioles often half as long as the leaf blade, or longer.
..........................................................................................46 Stamens 10 per flower; leaf blades with 4-6 pairs of main lateral veins; calyx sessile on mature fruit
............................................................................................47 Petiole usually 15-20 mm long; fruit not pruinose
............................................................................................47 Petiole usually 10-20 mm long; fruit usually pruinose
..........................................................................................46 Stamens 20 per flower; leaf blades with 3-4 pairs of main lateral veins; calyx collar often elevated on fruit.
..............................................................................................48 Flowers 8-10 mm wide; fruit ellipsoid
..............................................................................................48 Flowers 12-17 mm wide; fruit subglobose.
................................................................................................49 Leaf blades 20-30 mm long, often elliptic, apex acute
................................................................................................49 Leaf blades 30-40 mm long, usually rhombic or obovate, apex obtuse
........................................................................................45 Petioles mostly 1/3 or less as long as the leaf blade.
..................................................................................................50 Mature leaves pubescent or villous on veins.
....................................................................................................51 Terminal shoot leaves usually ovate or rhomboid.
......................................................................................................52 Stamens 10-15; styles 2 or 3; inflorescence slightly pubescent
......................................................................................................52 Stamens usually 20; styles 5; inflorescence branches canescent or tomentose.
........................................................................................................53 Terminal shoot leaves 4-6 cm long, often rhomboid
........................................................................................................53 Terminal shoot leaves 5-9 cm long, mostly ovate or oval.
..........................................................................................................54 Fruit yellow; [TX endemic]
..........................................................................................................54 Fruit red or orange-red; [collectively widespread, but not TX]
............................................................................................................55 Leaves flat, serrations large or coarse
............................................................................................................55 Leaves usually cupped, serrations small, acute
....................................................................................................51 Terminal shoot leaves mostly obovate or broadly elliptical.
..............................................................................................................56 Styles and pyrenes usually 2 or 3; primary leaf veins rather obscure or not impressed; petiole winged to base.
................................................................................................................57 Inflorescence tomentose; leaves pubescent abaxially; stamens 20
................................................................................................................57 Inflorescence villous or glabrate; leaves usually villous; stamens 10
..............................................................................................................56 Styles and pyrenes 3-5; primary leaf veins impressed adaxially, conspicuous abaxially; petiole winged near blade.
..................................................................................................................58 Stamens 10-20; anthers white or yellowish, rarely pink; sepals glandular-serrate.
....................................................................................................................59 Leaves usually unlobed; primary lateral veins usually 4 or 5 per side
....................................................................................................................59 Leaves shallowly lobed; primary lateral veins 5 or 6 per side
..................................................................................................................58 Stamens 20; anthers pink; sepals subentire.
......................................................................................................................60 Inflorescence stems glabrous; thorns > 3 cm long
......................................................................................................................60 Inflorescence stems hairy; thorns < 3 cm long
..................................................................................................50 Mature leaves glabrous or glabrate.
........................................................................................................................61 Primary leaf veins not impressed adaxially, somewhat obscure abaxially; petiole <10 mm long, winged to near base.
..........................................................................................................................62 Terminal shoot leaves 4.5-7 cm long; 1-3 styles and pyrenes.
............................................................................................................................63 Terminal shoot leaves elliptic to broadly obovate
............................................................................................................................63 Terminal shoot leaves often suborbicular
..........................................................................................................................62 Terminal shoot leaves mostly 2.5-4 cm long; 3-5 styles and pyrenes.
..............................................................................................................................64 Inflorescence pilose; stamens 20; anthers yellow
..............................................................................................................................64 Inflorescence sparsely hairy or glabrous; stamens usually 10-15; anthers usually pink
........................................................................................................................61 Primary leaf veins impressed adaxially, conspicuous abaxially; petiole 10 mm or more, partly winged near blade.
................................................................................................................................65 Leaf apex usually rounded; fruit 6-8 mm
................................................................................................................................65 Leaf apex acute; fruit 10 mm or more.
..................................................................................................................................66 Leaves with 6-9 pairs of main lateral veins; inflorescence villous or appressed-hairy.
....................................................................................................................................67 Leaf serrations acuminate, 2-3 mm long; 2-3 styles/pyrenes; branches dark gray
....................................................................................................................................67 Leaf serrations acute, 1-2 mm long; 3-5 styles/pyrenes; branches pale ashy-gray
..................................................................................................................................66 Leaves with 5-7 pairs of main lateral veins; inflorescence glabrous or slightly pubescent.
......................................................................................................................................68 Terminal shoot leaves sharply lobed; stamens usually 20
......................................................................................................................................68 Terminal shoot leaves barely lobed or unlobed; stamens 5-15.
........................................................................................................................................69 Leaves mostly rhomboid or suborbicular; stamens 5-10
........................................................................................................................................69 Leaves obovate, oblanceolate or elliptical; stamens 10-15.
..........................................................................................................................................70 Sepals glandular-serrate; stamens white, yellowish or pink.
..........................................................................................................................................70 Sepals subentire; anthers pink or purplish.
............................................................................................................................................71 Leaves often with 1-3 lobelike, asymmetrical points; styles 3 or 4
............................................................................................................................................71 Leaves unlobed; styles usually 2