Crataegus rivularis |
Crataegus lumaria |
|
---|---|---|
mountain river hawthorn, river hawthorn |
roundleaf hawthorn, thorny hawthorn |
|
Habit | Shrubs or trees, 30–50 dm. | Shrubs or trees, 50 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. |
twigs: new growth often ± reddish young, glabrous, 1-year old gray-brown, older dull gray; thorns on twigs ± recurved, 1-year old shiny, dark brown or black, older gray, slender, 2.5–7 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 length 40–60% blade, glabrous, sparsely to densely minutely glandular; blade green, broadly rhombic to rhombic-ovate, or narrowly ovate to broadly elliptic, 2–4(–5) cm, thin, base rounded to cuneate, lobes 3 or 4 per side, sinuses shallow, lobe apex acute, margins serrate, veins 4–6 per side, apex acute to obtuse, abaxial surface glabrous, adaxial glabrate young, soon glabrescent. |
Inflorescences | 6–12-flowered; branches glandular-punctate; bracteoles early caducous, usually present, margins sessile-glandular. |
6–15-flowered; branches pilose; bracteoles usually hyaline, linear, membranous, margins of proximal bracteoles usually stipitate-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. |
13–18 mm diam.; hypanthium glabrous; sepals narrowly triangular, 5 mm, margins entire, glandular; stamens 10, anthers ivory; styles 2 or 3. |
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. |
yellowish, dull orange, or reddish, suborbicular, 7–12 mm diam., glabrous; sepals reflexed; pyrenes 2 or 3. |
2n | = 68. |
|
Crataegus rivularis |
Crataegus lumaria |
|
Phenology | Flowering mid May–early Jun; fruiting Aug–Sep. | Flowering May; fruiting Sep–Oct. |
Habitat | Intermontane streamsides, ditches, flood plains | Brush, fallow pastures |
Elevation | 1300–2300 m (4300–7500 ft) | 30–300 m (100–1000 ft) |
Distribution |
AZ; CO; ID; NM; NV; UT; WY
|
MI; NY; WI; ON; QC |
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 lumaria is sporadic through much of its range; it is locally common in southern Ontario. Crataegus lumaria is much like a hairy-inflorescence form of C. dodgei. The disjunct C. jackii is a form with particularly hairy, suborbiculate leaves and larger flowers (to 20 mm). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 510. | FNA vol. 9, p. 604. |
Parent taxa | Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Douglasia > ser. Cerrones | Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Coccineae > ser. Rotundifoliae |
Sibling taxa | ||
Synonyms | C. dodgei var. lumaria, C. jackii | |
Name authority | Nuttall: in J. Torrey and A. Gray, Fl. N. Amer. 1: 464. (1840) | Ashe: J. Elisha Mitchell Sci. Soc. 19: 25. (1903) |
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