Flora of the Southeastern United States
2022 Edition

Colors

Data mode

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

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 pink; leaves shallowly lobed; [southern species]
............................................................................................................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

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