Crataegus sect. Crataegus
Shrubs or trees, 20–100 [–120] dm. Stems: trunks 1–few, ± erect, bark flattened-scaly or exfoliating; compound thorns on trunks present or absent; thorns on twigs determinate or indeterminate, straight or slightly curved, ± slender unless very short. Leaves: blade ± ovate, 1.2–6 cm, ± thin, lobes (0 or) 1–4 per side, sinuses shallow or deep, veins 2–8 per side, to lobes and sinuses, sometimes glossy. Inflorescences: branches glabrous or pubescent; symmetric bracteoles present, basal stipuliform, falcate bracteoles absent. Flowers: post-mature petals pale paper brown; stamens [10–] 20, anthers ivory, pale-yellow, pink to purple, or reddish. Pomes vermillion to red or orange-red [black]; pyrene sides plane or grooved.
Introduced; w Eurasia, n Africa, also in South America (Argentina), also in South America (Chile), s Africa, Pacific Islands (New Zealand), Australia
Species 28 (5 in the flora).
Four of the series recognized in sect. Crataegus are represented in the flora area.
Section Crataegus is extended here beyond ser. Crataegus to include three related North American series that have only determinate thorns and that have been suggested by E. Y. Y. Lo et al. (2009) to represent a separate subclade of hybrid origin.
|1||Veins to all sinuses; styles and pyrenes 1–3||> 2|
|1||Veins only to deeper sinuses; styles and pyrenes 3–5||> 3|
|2||Pomes bright to dark red, 6–14 mm diam., ± orbicular to ± cylindric; inflorescence branches glabrous; thorns on twigs indeterminate (when appearing terminal on often leafy twigs), sometimes determinate (aphyllous and lateral); trunk bark flattened-scaly, exfoliating in elongate strips; pyrene sides grooved.||64a.Crataegus ser. Crataegus|
|2||Pomes bright, glossy red, 4–6 mm diam., ellipsoid to sometimes orbicular; inflorescence branches densely pubescent; thorns on twigs determinate; trunk bark smooth, thin, exfoliating in irregular flakes; pyrene sides plane.||64a.Crataegus ser. Apiifoliae|
|3||Trunk bark flattened-scaly in elongate strips; leaf blades 3–6 cm, broad.||64a.Crataegus ser. Cordatae|
|3||Trunk bark exfoliating with smooth, thin flakes; leaf blades 1.5–3 cm, narrow.||64a.Crataegus ser. Microcarpae|