Crataegus pruinosa (H. L. Wendland) K. Koch var. delawarensis (Sargent) E. J. Palmer

Shrubs, 10–20 dm. Stems: twigs: new growth light green at first, pubescence not recorded, 1-year old dull red-brown, ˂marked by occasional large, oblong lenticels˃, 2-years old light gray-brown; thorns on twigs straight or slightly curved, 1-year old dark red-brown, slender, 3–4 cm. Leaves: ˂stipules linear, acuminate, coarsely glandular-serrate˃; petiole length not recorded, ˂distally slightly wing-margined, grooved˃, pubescence not recorded, glandular, ˂glands deciduous, few, dark red, small˃; blade ˂abaxial paler than adaxial, light yellow green adaxially˃, rhombic to ovate, 5–6 cm ˂length/width = 1.8–2˃, membranous, base narrowed from near mid blade, or base broadly cuneate and entire on vigorous shoots, lobes 3 or 4 per side distally, short, lobe apex acute, margins finely, sometimes doubly, serrate, ˂teeth gland-tipped˃, veins 3 or 4 per side, apex acute, surfaces glabrous. Inflorescences 5–8-flowered; branches glabrous; bracteoles ˂reddish, acute˃, margins glandular. Flowers 15 mm diam.; hypanthium usually glabrous, sometimes hairy; sepals broadly triangular, margins coarsely glandular-serrate, ˂apex acuminate˃; stamens 10, anthers pale yellow; styles 3 or 4, ˂arising from rough tomentum˃. Pomes dark red, suborbicular, 11–12 mm diam. ˂wider than tall, not pruinose˃; sepals closely appressed; pyrenes 3 or 4, dorsally prominently grooved.

Flowering Apr; fruiting Sep–Oct. Brush; of conservation concern; 20–100 m; Del.

Crataegus delawarensis is known only from northern Delaware; it differs from other members of the series by its narrow leaf blades and yellow anthers.