Crataegus (sect. Coccineae) ser. Greggianae
Monogr. N. Mex. Crataegus, 14. 1997.
Shrubs or trees, 40–80 dm, usually main trunk dominant. Stems: trunk bark buff to pale gray-brown, fibrous, checked into longitudinal plates, freshly exposed bark orangebrown; branches spreading, ± straight toward tips; twigs: new growth densely appressed-pubescent, 1-year old gray, sometimes ± shiny, 2-years old dull gray; thorns on twigs numerous, ± recurved, 2-years old shiny black, ± slender, 2.5–5 cm. Leaves: petiole length 25–33% blade, densely pubescent, eglandular; blade broadly ovate or broadly elliptic to rhombic-elliptic, 2.5–4 (–5) cm, chartaceous, base ± truncate or cuneate, lobes obscure or 1–3 per side, sinuses very shallow, lobe apex acute, margins serrate, venation craspedodromous, veins 4–6 per side, apex acute to subacute, abaxial surface glabrate to tomentose, pubescent on veins, adaxial pubescent young. Inflorescences 3–8-flowered, convex panicles; branches pubescent; bracteoles caducous, linear, membranous, margins stipitate-glandular. Flowers 15 mm diam.; hypanthium tomentose; sepals narrowly triangular, much shorter than petals, margins glandular-serrate; stamens 10 [–20], anthers pink or rose [or white]; styles [3–] 5. Pomes brick-red to bright red, suborbicular, 7–11 mm diam., pubescent; flesh mealy; sepals sometimes eroded, spreading when retained, nonaccrescent; pyrenes [2–] 5.
North America, Mexico, in Europe
Species 2 (1 in the flora).
Series Greggianae is restricted to the northern Sierra Madre Oriental, Mexico, and Edwards Plateau, Texas; it is found in dry and mesic scrub. The strictly Mexican species in the series is Crataegus serratissima J. B. Phipps.
Members of ser. Greggianae are similar to ser. Molles but are smaller leaved, smaller flowered, have less prominent bracteoles, and are more xeromorphic.