Flora of the Southeastern United States
2022 Edition

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Key to Crataegus, Key A: hawthorns with leaf blades widest below midpoint;
blade bases subcordate, truncate, rounded, or abruptly contracted

Click the number at the start of a key lead to highlight both that lead and its corresponding lead. Click again to show only the two highlighted leads. Click a third time to return to the full key with the selected leads still highlighted.

1 Primary lateral veins of lobed leaves run to sinuses between lobes as well as to points of lobes, in some or most leaves [see also Crataegus viridis].
..2 Leaves usually pubescent or villous abaxially or on petiole, especially when young; inflorescence hairy (villous, pubescent or tomentose).
....3 Styles usually 2; fruit < 9 mm broad, usually oval or elliptic in shape; [widespread species]
....3 Styles 3 to 5; fruit > 9 mm broad, subglobose; [rare Arkansas endemic nothospecies]
......4 Short-shoot leaf blades 2-3 cm long, often broad as long
......4 Short-shoot leaf blades 3-4 cm long, longer than broad
..2 Leaves and inflorescence glabrous [commonly cultivated species]
........5 Leaf lobes with few serrations; pyrene 1 per fruit; thorns usually 1-2 cm long; [exotic]
........5 Leaf lobes with numerous serrations; pyrenes 5 per fruit; thorns usually 3-5 cm long; [native]
1 Primary lateral veins of lobed leaves run only to lobe points, excepting on vigorous sprouts.
..........6 Sepals foliaceous, equal or exceeding petal length in flower and persistent on fruit
..........6 Sepals not foliaceous, much shorter than petals.
............7 Leaves abaxially with whitish hair tufts in proximal main vein axils, especially in spring; [Virides series and hybrids].
..............8 Leaves mostly ovate-lanceolate to elliptic, bases cuneate.
................9 Leaves and inflorescences pubescent
................9 Leaves glabrous, except for hair tufts.
..................10 Leaves predominately lanceolate
..................10 Leaves predominately elliptic or rhomboid
..............8 Leaves often ovate to rhomboid or suborbicular, bases cuneate or rounded.
....................11 Leaves glabrous except for hair tufts; most leaves ovate, unlobed, rounded at base
....................11 Leaves pubescent, particularly when young; leaves ovate or rhomboid, often lobed, bases cuneate; [interserial hybrids].
......................12 Leaves most pubescent adaxially, teeth and lobes sharp; sepals glandular-serrate
......................12 Leaves most pubescent abaxially; teeth and lobes subacute; sepals subentire.
........................13 Inflorescence glabrous or glabrate; anthers pink or reddish.
..........................14 Young leaves densely pubescent; leaves moderately lobed 10-25% to midrib
..........................14 Young leaves slightly pubescent; leaves shallowly lobed 10% to midrib
........................13 Inflorescence pubescent or villous; anthers white or yellowish.
............................15 Terminal shoot leaves ovate or rhomboid, lobed 20-50% to midrib
............................15 Terminal shoot leaves often suborbicular, lobed 20% or less to midrib.
..............................16 Terminal shoot leaves slightly lobed; inflorescence villous
..............................16 Terminal shoot leaves often unlobed; inflorescence pubescent
............7 Leaves lacking hair tufts; hairs, if present, dispersed over veins or surface of leaves.
................................17 Leaves abaxially pubescent, veins tomentose; petiole stout, pubescent, eglandular; inflorescence tomentose; [Molles series]
..................................18 Anthers pink or reddish.
....................................19 Anthers <1.5 mm long; fruit flesh dense; [rare Missouri endemic]
....................................19 Anthers 1.5-3 mm long; fruit usually soft-fleshed when mature; [widespread in southern Midwest]
..................................18 Anthers white or yellowish.
......................................20 Leaves barely lobed (5-10 % to midrib), base rounded or broadly cuneate
......................................20 Leaves moderately lobed (10-25 % to midrib), base truncate or subcordate on terminal shoots.
........................................21 Fruit usually red; leaves plane; [widespread species]
........................................21 Fruit usually yellow; leaves cupped; [east Texas endemic]
................................17 Leaves variously pubescent or glabrous; petiole typically glandular, particularly in spring; inflorescence pubescent or glabrous.
..........................................22 Leaf blades on terminal shoots commonly 8-12 cm long.
............................................23 Inflorescence densely pubescent.
..............................................24 Leaf base usually truncate; anthers pinkish; habit arborescent
..............................................24 Leaf base often broadly cuneate; anthers white or ivory; habit usually shrubby
............................................23 Inflorescence slightly pubescent or glabrous.
................................................25 Leaf blades often wide as long; stamens usually 20; petiolar glands stalked; sepals pectinate
................................................25 Leaf blades longer than broad; stamens 5-10; petiolar glands sessile, small or sparse; sepals glandular-serrate.
..................................................26 Sepals evenly glandular-serrate; fruit subglobose
..................................................26 Sepals irregularly glandular-serrate; fruit oblong
..........................................22 Leaf blades on terminal shoots usually < 8 cm long.
....................................................27 Petiole distinctly villous or pubescent, particularly early in growing season.
......................................................28 Pyrenes usually 2 or 3, concave or pitted on inner sides; [interserial hybrids].
........................................................29 Leaves scabrate adaxially when young; stamens 7-10; [northern taxa rare in SE]
........................................................29 Leaves pubescent to villous; stamens 10 or 20; [Crataegus calpodendron hybrid endemics of MO and AR]
..........................................................30 Leaves 6-8 cm long, ovate, lobes obtuse
..........................................................30 Leaves 3-5 cm long, often rhomboid, lobes acute
......................................................28 Pyrenes usually 4 or 5, plane on inner sides.
............................................................31 Terminal shoot leaves ovate or tending toward oval or suborbicular, unlobed or very shallowly lobed.
..............................................................32 Petiole eglandular or remotely glandular, unwinged for most of its length; [Molles interserial hybrids]
................................................................33 Leaves mostly ovate, shallowly lobed 10-20% to midrib; fruit 8-10 mm
................................................................33 Leaves mostly oval or suborbicular, unlobed or lobed to 10% to midrib; fruit 10-18 mm
..............................................................32 Petiole with several conspicuous stalked glands, winged near half its length.
..................................................................34 Terminal shoot leaves suborbicular, mostly unlobed; inflorescence >10-flowered
..................................................................34 Terminal shoot leaves very shallowly lobed; inflorescence 3- to 8-flowered
............................................................31 Terminal shoot leaves broadly ovate or deltate, often lobed 20% or more to midrib.
....................................................................35 Sepals partly glandular-serrate or subentire; leaves often deltate.
......................................................................36 Leaves often broad as long, densely villous adaxially in spring; [AR endemic]
......................................................................36 Leaves longer than broad, sparsely villous adaxially in spring; [widespread taxa].
........................................................................37 Stamens 5 or 10; calyx sessile on fruit
........................................................................37 Stamens 20; calyx collar usually elevated on fruit
....................................................................35 Sepals deeply gland-toothed or pectinate; most leaves ovate.
..........................................................................38 Stamens 20; leaves densely pubescent
..........................................................................38 Stamens 10; leaves villous or sparsely hairy.
............................................................................39 Leaves 3-6 cm long; anthers whitish; calyx collar elevated on fruit
............................................................................39 Leaves mostly 2-3 cm long; anthers reddish; calyx near sessile on fruit
....................................................27 Petiole glabrous, or at most only sparsely hairy in spring
..............................................................................40 Calyx sessile on mature fruit.
................................................................................41 Terminal shoot leaves commonly deltate; petiole length often 50-75% as long as blade
..................................................................................42 Leaves adaxially minutely strigose when young, abaxially glabrous
....................................................................................43 Inflorescence often slightly villous
....................................................................................43 Inflorescence glabrous.
......................................................................................44 Flesh of mature fruit dense or hard; [northern taxa rare in Southeast].
........................................................................................45 Terminal shoot leaves incised 25-50% to midrib, distal 2 or 3 lobe tips alligned
........................................................................................45 Terminal shoot leaves incised 10-30% to midrib, distal lobe tips convex in outline
......................................................................................44 Flesh of mature fruit soft, succulent; [taxa widely distributed in Southeast]
..........................................................................................46 Stamens 5-10 per flower
..........................................................................................46 Stamens 15-20 per flower
..................................................................................42 Leaves adaxially glabrous or remotely pubescent or strigose on veins of both surfaces
............................................................................................47 Stamens 15-20 per flower
............................................................................................47 Stamens 5-10 per flower.
..............................................................................................48 Flowers 12-15 mm diameter; thorns often angled <90° from twig
..............................................................................................48 Flowers 15-22 mm diameter; thorns usually ~ 90 ° from twig.
................................................................................................49 Leaf blades mostly 4-7 cm long; twigs and fruits not pruinose
................................................................................................49 Leaf blades usually 2-5 cm long; twigs and fruits often pruinose
................................................................................41 Terminal shoot leaves mostly ovate or near rhombic; petiole length mostly 30-50 % as long as blade.
..................................................................................................50 Petiole distinctly and persistently glandular.
....................................................................................................51 Inflorescence scabrous-pubescent; petiolar glands stipitate
....................................................................................................51 Inflorescence sparsely hairy or glabrate; petiolar glands sessile.
......................................................................................................52 Stamens usually 20; leaves sharply lobed 10-40 % to midrib
......................................................................................................52 Stamens 10; leaves unlobed or lobed <25 % to midrib.
........................................................................................................53 Leaves and inflorescences sparsely hairy
........................................................................................................53 Leaves and inflorescences glabrous
..................................................................................................50 Petiole eglandular or rarely with 1 or 2 glands in spring.
..........................................................................................................54 Stamens 10-15.
............................................................................................................55 Anthers yellow; leaves moderately lobed; [endemic of n. DE]
..........................................................................................................54 Stamens 20; [Virides series].
..............................................................................................................56 Fruit 10-15 mm; anthers <1 mm long; most leaves ovate-lanceolate
..............................................................................................................56 Fruit 5-10 mm; anthers 1-2 mm long; most leaves ovate or rhombic
..............................................................................40 Calyx collar elevated on mature fruit
................................................................................................................57 Petiole remotely glandular in spring; sepals remotely glandular-serrate or subentire; [Pruinosae series]
..................................................................................................................58 Leaves finely crenate-serrate, barely lobed; petiole often nearly as long as blade
..................................................................................................................58 Leaves sharply or coarsely toothed and lobed; petiole usually < 2/3 as long as blade
....................................................................................................................59 Leaf blades usually 2-4 cm long; terminal shoot leaf blades usually 3-5 cm long.
......................................................................................................................60 Leaves slightly hairy, later glabrate; inflorescence slightly villous
......................................................................................................................60 Leaves and inflorescence glabrous.
........................................................................................................................61 Leaves mostly deltate or broadly ovate; [AR endemic]
........................................................................................................................61 Leaves ovate to near rhombic; [mostly of northeastern US]
....................................................................................................................59 Leaf blades usually 3-5 cm long; terminal shoot leaf blades often 4-7 cm long.
..........................................................................................................................62 Stamens 10 per flower; calyx slightly elevated on fruit
..........................................................................................................................62 Stamens 20 per flower; calyx distinctly elevated on fruit.
............................................................................................................................63 Leaf blades often 5-7 cm long, lobes obscure; [rare taxon]
............................................................................................................................63 Leaf blades mostly 3-5 cm long, shallowly to moderately lobed; [widespread taxa]
..............................................................................................................................64 Leaf base truncate to subcordate; lvs often as wide as long
..............................................................................................................................64 Leaf base truncate or abruptly tapered; lvs longer than wide.
................................................................................................................................65 Anthers ca. 0.5mm long; leaves elongate distally
................................................................................................................................65 Anthers ca. 1-2mm long; leaves ovate, not elongate distally
................................................................................................................57 Petiole distinctly and persistently glandular; sepals distinctly glandular-serrate.
..................................................................................................................................66 Stamens 5 to 10; [Intricatae series].
....................................................................................................................................67 Anthers white or yellow.
......................................................................................................................................68 Sepals glandular-serrate distally; terminal shoot leaves deltate
......................................................................................................................................68 Sepals wholly glandular-serrate; terminal shoot leaves ovate.
........................................................................................................................................69 Calyx collar distinctly elevated on fruit; [eastern taxa]
........................................................................................................................................69 Calyx collar slightly elevated or near sessile on fruit; [midwestern taxa]
....................................................................................................................................67 Anthers pink, rose, or purple.
..........................................................................................................................................70 Sepals often partly glandular-pectinate; terminal shoot leaves broadly ovate or deltate.
............................................................................................................................................71 Sepals pectinate near base; leaf lobes obtuse; trunk bark often furrowed
............................................................................................................................................71 Sepals pectinate near tip; leaf lobes sharp; trunk bark usually scaly
..........................................................................................................................................70 Sepals glandular-serrate; terminal shoot leaves ovate or less commonly broadly ovate.
..............................................................................................................................................72 Anthers purplish; sepals finely glandular-serrate
..............................................................................................................................................72 Anthers pink; sepals deeply glandular-serrate.
................................................................................................................................................73 Fruit globose, 12-14 mm long, yellow; leaves subcoriaceous
................................................................................................................................................73 Fruit obovoid, 10-12 mm long, red or ruddy; leaves thin
..................................................................................................................................66 Stamens 15-20; [Pulcherrimae series].
..................................................................................................................................................74 Leaves mostly unlobed and apex obtuse; terminal shoot leaves lobed 5-10% to midrib
..................................................................................................................................................74 Leaves shallowly lobed, or if unlobed then apex acute; terminal shoot leaves lobed 10-60% to midrib.
....................................................................................................................................................75 Leaves ovate-lanceolate; margin outline nearly straight from about mid-blade to apex.
......................................................................................................................................................76 Terminal shoot leaves with 4 or 5 pairs of distinct lobes; often a suckering shrub
......................................................................................................................................................76 Terminal shoot leaves with 3 to 4 pairs of shallow lobes; usually arborescent
....................................................................................................................................................75 Leaves ovate, broadly ovate or near rhombic or suborbicular; margin outline convex.
........................................................................................................................................................77 Petioles of smaller leaves winged 1/2 length; fruit often 10-15 mm.
..........................................................................................................................................................78 Anthers purplish; fruit ovoid or oval, yellow
..........................................................................................................................................................78 Anthers white or yellow; fruit globose, ruddy to dull red
........................................................................................................................................................77 Petioles of smaller leaves winged 1/3 or less of length; fruit usually <10 mm.
............................................................................................................................................................79 Terminal shoot leaf blades often broad as long, lobes rounded
............................................................................................................................................................79 Terminal shoot leaf blades longer than broad, lobes obtuse to acute