Crataegus sect. Macracanthae
Arbor. Frutic. Brit. 2: 819. 1838.
Shrubs or trees, 20–70 (–80) dm. Stems: trunks 1–several, ± erect to oblique, bark flattened-scaly; compound thorns on trunks present or absent; thorns on twigs determinate, recurved, usually stout, sometimes ± slender. Leaves: blade ± ovate or rhombic to rhombic-elliptic or broadly elliptic, 3–8 (–12) cm, coriaceous or thin, lobes 0 or 3–5 (–8) per side, sinuses shallow, max LII usually 20%, veins (3–) 5–8 per side, absent to sinuses. Inflorescences: branches usually pubescent; symmetric bracteoles present, basal bracteoles absent, falcate bracteoles absent. Flowers: post-mature petals pale paper brown; stamens 10 or 20, anthers red, pink, purple, sometimes white, ivory, or cream. Pomes orange to red; pyrenes dorsally grooved, sides ± pitted or eroded, sometimes plane.
Distribution
North America
Discussion
Species 8 (8 in the flora).
Section Macracanthae is similar to some species of sect. Coccineae; it differs in possessing more or less pitted pyrenes.
Selected References
None.
Lower Taxa
Key
1 | Pyrenes 2 or 3, (obtuse at ends), sides eroded; petioles usually eglandular. | Crataegus ser. Macracanthae |
1 | Pyrenes 2–5, (obtuse or acute at ends), sides ± smooth to erose or pitted; petioles usually glandular | > 2 |
2 | Pyrene sides eroded, (always obtuse at ends); Great Plains. | Crataegus ser. Macracanthae |
2 | Pyrene sides ± smooth to erose or pitted, (sometimes acute at ends); Great Lakes to New England. | 64e.Crataegus ser. Anomalae |
"thin" is not a number."adnate" is not a number."dm" is not declared as a valid unit of measurement for this property.