Crataegus (sect. Crataegus) ser. Apiifoliae
Man. Cult. Trees ed. 2, 367. 1940.
Shrubs or trees, 20–80 dm often with crown of ± layered branches. Stems: trunk bark particolored, smooth, thin, exfoliating in irregular flakes; compound thorns on trunks absent; thorns on twigs determinate. Leaves: petiole length 80–150% blade; blade broadly ovate to deltate, lobes 3 per side at 45°–70° angle with midvein, sinuses deep, venation craspedodromous, veins to major sinuses. Inflorescences 4–10-flowered; branches densely pubescent; bracteoles caducous, linear, small, membranous, margins irregularly toothed, teeth gland-tipped. Flowers 12–17 mm diam.; sepals narrowly triangular; petals elliptic; stamens 20, anthers reddish; styles 1 or 2 (or 3). Pomes bright red, ellipsoid to sometimes orbicular, 4–6 mm diam., glossy; flesh mealy when ripe; sepal remnants persistent; pyrenes 1 or 2 (or 3), dorsally convex, sides plane.
se United States
Series Apiifoliae is widespread and common and has obvious similarities to European ser. Crataegus in the distinctive leaf shape, relatively small flowers, long filaments, and small, few-pyrened fruit; it differs from the latter series in possessing only determinate thorns.