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Key to Crataegus, Key B: hawthorns with leaf blades widest at midpoint or beyond midpoint; blade bases acute or cuneate;
leaves conspicuously glandular on petiole and teeth; twigs and branchlets geniculate

Rosaceae

Crataegus

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1 Leaf blades usually < 12 mm wide and < 2 cm long (on floreal shoots).
  2 Leaf blades often nearly wide as long, blade broadly obovate or suborbicular.
    3 Leaves denticulate or remotely toothed, rarely lobed; petiole glabrate; shrub usually < 1m tall
    3 Leaves sharply toothed, often lobed; petiole hairy; shrub or tree > 1 m tall
  2 Leaf blades 1.5-2× long as broad, mostly spatulate or oblanceolate.
      4 Leaves and flower pedicels pubescent to tomentose.
          6 Thorns 1-3 cm long; plant usually < 1 m tall
          6 Thorns 3-6 cm long; plant usually 1-2 m tall
1 Leaf blades mostly > 12 mm wide and > 2 cm long.
             7 Leaf margin mostly subentire; may have glandular-denticulate teeth or 3 lobelike points on distal part of blade.
               8 Leaves often with 3 lobelike points near apex.
               8 Leaves denticulate or subentire to apex, rarely with any lobelike points.
                   10 Thorns abundant, present at nearly every node and > 3 cm long
                   10 Thorns less numerous, most < 3 cm long.
             7 Leaf margin toothed along at least half of margin, the teeth fine, acute, obtuse or dentate.
                       12 Floreal leaves often rhomboid or broadly elliptical; twigs and branches usually not drooping.
                          13 Leaves distinctly sharply toothed and/or lobed; blades broadly ovate on terminal shoots and > 3.5 cm long
                          13 Leaves with small or blunt teeth, mostly unlobed; blades rhombic, obovate or orbicular on terminal shoots, < 3.5 cm long.
                            14 Stamens 10 per flower; terminal shoot leaves broadly rhombic to suborbicular
                       12 Floreal leaves mostly obovate or spatulate; leading twigs or branches drooping or pendulous.
                              15 Leaf apex rounded or with an abrupt short point, margins finely or sharply toothed beyond middle of blade; terminal shoot leaves unlobed to very obscurely lobed.
                              15 Leaf apex 3-lobed or with 3-5 distinct points or several larger teeth; terminal shoot leaves moderately to deeply lobed.
                                               23 Leaves obovate or sub-rhombic, with 3-5 pairs of main lateral veins; fruit 12-15 mm, flesh soft.