Crataegus rivularis |
Crataegus prona |
|
---|---|---|
mountain river hawthorn, river hawthorn |
Illinois hawthorn |
|
Habit | Shrubs or trees, 30–50 dm. | Shrubs or trees, 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. |
twigs: new growth reddish green, glabrous, 1-year old reddish brown, sometimes very dark, older mid gray; thorns on twigs recurved, 2-years old dark blackish red, ± shiny, ± slender, 3–5 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 2–4 cm, glabrous, eglandular or sparsely glandular; blade deltate-ovate to ovate, 4–7 cm length/width = 1.1–1.2, subcoriaceous, base broadly rounded to ± cuneate, lobes 3–5 per side, sinuses usually shallow, lobe apex acute, margins strongly serrate, veins 5 or 6 per side, apex acute to acuminate, surfaces glabrous except adaxial appressed-hairy young. |
Inflorescences | 6–12-flowered; branches glandular-punctate; bracteoles early caducous, usually present, margins sessile-glandular. |
5–12-flowered; branches glabrous; bracteoles few, 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. |
16–18 mm diam.; hypanthium glabrous; sepals narrowly triangular, 5–6 mm, margins subentire, abaxially glabrous; stamens 6–10, anthers red to 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. |
reddish orange to bright red, suborbicular to oblong, 8–11 mm diam.; sepals patent-reflexed or commonly erose; pyrenes 3 or 4, dorsally grooved. |
Crataegus rivularis |
Crataegus prona |
|
Phenology | Flowering mid May–early Jun; fruiting Aug–Sep. | Flowering May; fruiting Sep–Oct. |
Habitat | Intermontane streamsides, ditches, flood plains | Brush |
Elevation | 1300–2300 m (4300–7500 ft) | 100–300 m (300–1000 ft) |
Distribution |
AZ; CO; ID; NM; NV; UT; WY
|
IN; MI; NY; PA; WI; ON |
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 prona ranges from Wisconsin and Indiana through Michigan to New York and Pennsylvania. Crataegus prona is similar to C. populnea but with proportionately wider leaves and narrow pomes. When better known, it may prove the same as C. populnea. Crataegus gravis is a form with more oblong fruit and smaller leaves with sharper lobes. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 510. | FNA vol. 9, p. 570. |
Parent taxa | Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Douglasia > ser. Cerrones | Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Coccineae > ser. Populneae |
Sibling taxa | ||
Synonyms | C. gravis | |
Name authority | Nuttall: in J. Torrey and A. Gray, Fl. N. Amer. 1: 464. (1840) | Ashe: J. Elisha Mitchell Sci. Soc. 19: 17. (1903) |
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