Crataegus (sect. Sanguineae) ser. Altaicae
J. Bot. Res. Inst. Texas 3: 243. 2009.
[Shrubs or] trees, 30–60 dm. Stems: 1-year old twigs deep red- or purple-brown, shining, older dull or dark gray. Leaves deciduous; petiole length 1/5–1/3 blade; blade ± ovate, 5–9 cm, base truncate to broadly cuneate, lobes 3–5 per side, sinuses shallow to deep (if deep, usually only proximal 1–2), margins sharply serrate, venation craspedodromous, veins 4 or 5 per side, to lobes and deeper sinuses, apex acute. Inflorescences 20–50-flowered; branches often warty; bracteoles absent or present, caducous, linear to elliptic, membranous, margins glandular; basal branches subtended by persistent, chlorophyllous, falcate, stipuliform, glandular bracteoles. Flowers 12–15 mm diam.; sepals triangular-ovate, short, entire or 1- or 2-toothed; filament length usually 2 times petals; styles 4 or 5. Pomes yellow or orange [to red or reddish], suborbicular; sepals reflexed; pyrenes 4 or 5.
Introduced; Wash., c Asia.
Species 2 or 3 (1 in the flora).
Series Altaicae is closely related to ser. Sanguineae; its glabrous inflorescences, unusual fruit color, and distribution combine to distinguish it.