Crataegus sect. Crataegus
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.
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.
branches glabrous or pubescent;
symmetric bracteoles present, basal stipuliform, falcate bracteoles absent.
post-mature petals pale paper brown;
stamens [10–]20, anthers ivory, pale yellow, pink to purple, or reddish.
vermillion to red or orange-red [black];
pyrene sides plane or grooved.
Crataegus sect. Crataegus
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.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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. | C. 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. | C. ser. Apiifoliae |
3. Trunk bark flattened-scaly in elongate strips; leaf blades 3–6 cm, broad. | C. ser. Cordatae |
3. Trunk bark exfoliating with smooth, thin flakes; leaf blades 1.5–3 cm, narrow. | C. ser. Microcarpae |
