Crataegus reverchonii

Sargent

Trees & Shrubs 1: 55, plate 28. 1903.

Common names: Reverchon hawthorn
EndemicIllustrated
Treatment appears in FNA Volume 9. Treatment on page 537. Mentioned on page 534.
Revision as of 22:33, 13 August 2020 by RevisionBot (talk | contribs) (Bot: Adding category Revision Pending)

Shrubs, 10–30(–80) dm. Stems: twigs: new growth glabrous, 1-year old dark gray; thorns on twigs slightly reflexed, 2-years old blackish, usually stout, 3–6 cm. Leaves: petiole 2–5 mm, length 7–11% blade, glabrous, eglandular; blade (on extension shoots) ± orbiculate to broadly elliptic, (on short shoots) ± orbiculate to broadly oblong-elliptic, 2–6 cm, very coriaceous, base broadly cuneate, lobes 0, margins serrulate in distal 1/2, venation semicamptodromous, veins 5 or 6 per side, apex subacute to obtuse, surfaces sparsely hairy young, glabrescent. Inflorescences 8–15-flowered; branches usually glabrous; bracteoles linear, small, margins short-stipitate-glandular. Flowers 8–12 mm diam.; hypanthium glabrous, sometimes slightly pilose; sepals 4 mm, margins subentire, abaxially glabrous; stamens 10–15(–20), anthers cream, rose, or red; styles (2 or)3–5. Pomes red to orange-red, suborbicular, 10 mm diam., glabrous; sepals persistent, patent or reflexed; pyrenes (1–)3–5.

Distribution

V9 901-distribution-map.jpg

Ala., Ark., Del., Ga., Kans., La., Miss., Mo., Okla., Tenn., Tex.

Discussion

Varieties 3 (3 in the flora).

Crataegus reverchonii is differentiated from C. crus-galli by a greater number of styles and pyrenes (except for var. mohrii) and extension-shoot leaves that tend to be suborbiculate. Distinction from a small-leaved form of C. crus-galli from the Edwards Plateau, Texas, needs elucidation. Crataegus stevensiana is sometimes separated out as a variety or species; however, the complex, unresolved variation makes this distinction moot at the moment.

The principal variation within Crataegus reverchonii is between smaller-statured, smaller-leaved, smaller-fruited, more-styled, xeromorphic plants of the southwest (var. reverchonii), and larger-leaved, large-flowered, fewer-styled plants of the mid latitude, eastern United States (var. palmeri). Variety mohrii is intermediate.

Selected References

None.

Key

1 Short-shoot leaf blades 4–6 cm; flowers 10–12 mm diam.; styles (2 or)3. Crataegus reverchonii var. palmeri
1 Short-shoot leaf blades 2–3.5 cm; flowers 8–12 mm diam.; styles 3–5 > 2
2 Flowers 8–10 mm diam.; inflorescences usually glabrous; w of Mississippi River. Crataegus reverchonii var. reverchonii
2 Flowers 12 mm diam.; inflorescences often pilose; e of Mississippi River. Crataegus reverchonii var. mohrii