Crataegus rivularis |
Crataegus colonica |
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mountain river hawthorn, river hawthorn |
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Habit | Shrubs or trees, 30–50 dm. | Shrubs, 15–30 dm, branches ± weeping. |
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 ashy gray, rough or scaly; twigs: new growth densely white-canescent, 1-year old purple-brown or blackish, older dark gray, ± stout; thorns on twigs usually numerous, straight or slightly recurved, 1-year old blackish or purple-brown, moderately stout, 2–4.5 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 length 15% blade, winged distally, densely pubescent, glandularity not recorded; blade obovate, 1.5–2.5(–3) cm, stiff, ± coriaceous, base gradually tapered, lobes 0, margins basally entire or subentire, distally ± denticulate, veins 2–4(or 5) per side (except smaller leaves), apex acute and ± cuspidate to ± obtuse, abaxial surface white-tomentose at anthesis, particularly on veins, adaxial glabrescent. |
Inflorescences | 6–12-flowered; branches glandular-punctate; bracteoles early caducous, usually present, margins sessile-glandular. |
2–4-flowered; branches tomentose; bracteoles oblong-linear, margins sessile-glandular, adaxially thin pubescent. |
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. |
12–15 mm diam.; hypanthium tomentose; sepals narrowly triangular, 4 mm, margins finely glandular-serrate, abaxially ± tomentose; anthers cream or ivory; styles 3–5. |
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. |
green turning red or blushed red, pyriform or suborbicular, 6–9 mm diam., pubescent; sepals spreading; pyrenes 3–5. |
Crataegus rivularis |
Crataegus colonica |
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Phenology | Flowering mid May–early Jun; fruiting Aug–Sep. | Flowering early to mid Apr; fruiting Aug. |
Habitat | Intermontane streamsides, ditches, flood plains | Sand hills, dry sandy woodlands, sandy roadsides |
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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NC; 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 colonica is particularly abundant in south-central North Carolina. Very thorny species are unusual in ser. Lacrimatae, and C. colonica shares this, as well as habit, small leaves, and distribution with C. pexa. From the latter, it is distinguished by a distinctive leaf shape reminiscent of forms of C. crus-galli, relatively small, more or less pyriform fruits and shorter and less often numerous thorns. Crataegus colonica and C. pexa could represent two poles of the same species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 510. | FNA vol. 9, p. 627. |
Parent taxa | Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Douglasia > ser. Cerrones | Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Coccineae > ser. Lacrimatae |
Sibling taxa | ||
Synonyms | C. lassa var. colonica | |
Name authority | Nuttall: in J. Torrey and A. Gray, Fl. N. Amer. 1: 464. (1840) | Beadle: Biltmore Bot. Stud. 1: 104. (1902) |
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