Crataegus rivularis |
Crataegus egregia |
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mountain river hawthorn, river hawthorn |
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Habit | Shrubs or trees, 30–50 dm. | Trees, 40–60 dm. |
Stems | twigs: new growth greenish, sparsely pubescent, early glabrescent, 1–2-years old often red-purple; bark on younger 2–5 cm thick branches dark gray-brown, sometimes copper-colored; thorns on twigs straight or ± recurved, 2-years old black or purple-black, glossy, fine, 1.5–4 cm. |
trunk bark dark, very rough; twigs ± flexuous, new growth pubescent, 1-year old brown, older grayish; thorns on twigs absent or several, straight, 1–2-years old dark, slender, 3–4 cm. |
Leaves | petiole 1–2.5 cm, glabrous; blade elliptic to narrowly elliptic, 3–8 cm, length 2+ times width, thin, base cuneate, lobes 0 or small apiculi at ends of some vein tips, margins serrate, teeth numerous, usually acute, fine to coarse, venation semicamptodromous, veins 4 or 5 per side, larger often branched proximal to ends, apex acute, abaxial surface glabrous, adaxial appressed-strigose young. |
petiole slender, length 30–50% blade, pubescent, very sessile-glandular; blade rhombic, 1.5–2.5 cm anthesis, 2–3 cm mature, thin, base cuneate, lobes 1(or 2) per side, sinuses moderately deep, well defined, lobe apex acute to ± obtuse, margins shallowly crenate, teeth gland-tipped, veins 3 per side, apex acute to subacute, abaxial surface glabrate, adaxial sparsely hairy young, glabrescent. |
Inflorescences | 6–12-flowered; branches glandular-punctate; bracteoles early caducous, usually present, margins sessile-glandular. |
3-flowered; branches hairy; bracteoles caducous, greenish, narrowly oblong, margins glandular. |
Flowers | 14–17 mm diam.; sepals broadly deltate, 6–8 mm, margins entire, apex narrow, glabrous; stamens 10, anthers pink, sometimes ivory; styles 3–5. |
15 mm diam.; hypanthium sparsely pilose; sepals narrowly triangular from wide bases, margins subentire to glandular on barely discernible teeth, abaxially glabrous; stamens 20, anthers bright purple; styles 3 or 4. |
Pomes | deep red (mid Aug), black or blackish purple mature, suborbicular, 10 mm diam.; sepals ± erect to strongly outcurved or ± patent, 2–3 mm; pyrenes 3 or 4, sides eroded. |
red, slightly pyriform, 9–12 mm diam., glabrous; sepals reflexed; pyrenes 3 or 4. |
Crataegus rivularis |
Crataegus egregia |
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Phenology | Flowering mid May–early Jun; fruiting Aug–Sep. | Flowering Apr; fruiting Sep–Oct. |
Habitat | Intermontane streamsides, ditches, flood plains | Open brush, open woodlands |
Elevation | 1300–2300 m (4300–7500 ft) | 0–100 m (0–300 ft) |
Distribution |
AZ; CO; ID; NM; NV; UT; WY
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AL; FL; GA; SC |
Discussion | Crataegus rivularis is most abundant in intermontane Colorado and Utah and is one of two hawthorns found in Arizona; it is rare in Nevada. There are reports from northwestern Texas (for example, D. S. Correll and M. C. Johnston 1970); they have not been verified. Crataegus rivularis is one of the more common woody species of mesic, valley bottom intermontane habitats. The species flowers early. Crataegus rivularis is superficially similar to the more or less sympatric, less common, C. saligna; it has larger leaves with fewer veins, larger flowers with ten stamens, and larger pomes. It differs from C. erythropoda little other than in leaf shape and ripe fruit color. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Crataegus egregia was described from Bristol, Florida, and is understood primarily from its type. It is in some ways like C. egens (ser. Lacrimatae) but with larger, more rhombic leaf blades, purple anthers, and where present, longer thorns. South Carolina specimens are thorny; the type material is thornless. Material represented by about six specimens, with similar leaves but more or less tomentose pedicels and much smaller pomes, is also known. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 510. | FNA vol. 9, p. 613. |
Parent taxa | Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Douglasia > ser. Cerrones | Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Coccineae > ser. Apricae |
Sibling taxa | ||
Name authority | Nuttall: in J. Torrey and A. Gray, Fl. N. Amer. 1: 464. (1840) | Beadle: Biltmore Bot. Stud. 1: 82. (1902) |
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