Crataegus (sect. Douglasia) ser. Cerrones
Canad. J. Bot. 76: 1872. 1999.
Shrubs or trees, 30–50 dm. Stems: twigs: new growth glabrous or sparsely hairy, 1-year old reddish tan, reddish mahogany, or red-purple, older gray or copper-colored; bark on younger 2–5 cm thick branches mainly dark gray-brown or copper-colored, horizontal lenticels present; thorns on twigs straight or recurved, 2-years old black or purple-black, glossy or shiny, slender, 1–4 cm. Leaves: petiole slender, 0.8–2.5 cm, pubescence and glandularity not recorded; blade ± elliptic to rhombic-elliptic, 3–8 cm, thin to coriaceous, base cuneate, lobes 0 or 3 or 4 per side, sinuses shallow, lobe apex acute, margins shallowly crenate or serrate, venation craspedodromous to semicamptodromous, veins 4 or 5 (–12) per side, apex usually acute, sometimes obtuse, abaxial surface glabrate or glabrous mature. Inflorescences 5–12-flowered; branches glabrous, usually glandular-punctate; bracteoles caducous, linear, membranous, margins usually sessile-glandular, sometimes eglandular. Flowers (10–) 14–18 mm diam.; hypanthium glabrous; sepals (1.5–) 3–4 (–8) mm, margins subentire or entire; stamens 10 (or 20), anthers pink or pink-purple to purple, sometimes cream; styles 3–5. Pomes deep red to vinous purple or black, orbicular, (8–) 10 mm diam., glabrous; sepals suberect to reflexed; pyrenes 3–5, sides excavated.
w United States
Species 3 (3 in the flora).
Series Cerrones was initially treated among the red-fruited series (J. B. Phipps 1999b) as it was then understood only from its type species, Crataegus erythropoda, which has the least typical fruit color for the series. Series Cerrones contains two closely related species of intermontane hawthorn to which C. saligna, formerly placed in ser. Brachyacanthae, has been added. Series Cerrones is characterized by copper-colored mature bark, sometimes displaying horizontal lenticels, fine and short thorns, early caducous, few gland-margined bracteoles, burgundy to black mature fruit, and pyrenes with lateral excavations.
|1||Leaf blades: veins 6–9(–12) per side, margins crenate; flowers 10–13 mm diam., stamens 20, anthers cream.||Crataegus saligna|
|1||Leaf blades: veins 4 or 5 per side, margins serrate; flowers 14–18 mm diam., stamens 10, anthers usually pink to pink-purple or purple, sometimes ivory||> 2|
|2||Leaf blades rhombic-elliptic, l/w = 1.6, lobes 3 or 4 per side; pomes deep red to vinous purple mature.||Crataegus erythropoda|
|2||Leaf blades elliptic to narrowly elliptic, at least 2 times as long as wide, lobes 0 or with small apiculi at ends of some vein tips; pomes black or blackish purple mature.||Crataegus rivularis|