Crataegus sect. Apiifoliae Loudon, Arbor. Frutic. Brit. 2: 824. 1838

Shrubs or trees, 20–80 dm ˂often with crown of ± layered branches˃. Stems: trunk bark parti-colored, 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.

Species 1: 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.