Crataegus rivularis |
Crataegus beata |
|
---|---|---|
mountain river hawthorn, river hawthorn |
dunbar's hawthorn |
|
Habit | Shrubs or trees, 30–50 dm. | Shrubs, 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 dark orange-green tinged with red, glabrous, 1-year old bright reddish brown, older mid gray; thorns on twigs straight to slightly recurved, 2-years old dark, shiny reddish brown, stout, 3.5–4.5 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 2.5–4 cm, hairy young, glabrescent, ± densely glandular; blade broadly ovate to deltate-ovate, 5–8 cm, subcoriaceous, base broadly rounded to subtruncate, sometimes broadly cuneate, lobes 4 or 5 per side, ± triangular, sinuses not recorded, lobe apex acute to acuminate, margins strongly serrate, veins 5 per side, apex 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, margins subentire or slightly glandular, abaxially glabrous; stamens 20, anthers deep maroon; 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. |
crimson, oblong to oblong-obovoid, 9–10 mm diam.; sepals spreading; pyrenes 4 or 5, dorsally grooved. |
Crataegus rivularis |
Crataegus beata |
|
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
|
MI; NY; OH; 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 beata is a rare, variable taxon that here comprises all the 20-stamen forms of ser. Populneae and may be more widespread than indicated. Syntype material has resemblances to C. schuettei and C. stolonifera. The very small amount of material available to the author is characterized by tan or very dark (brownish to blackish) one-year old wood and one-year thorns, sharply dissected, narrower, C. levis-like leaves, or more shallowly incised (except in extension shoots) C. populnea-like coriaceous foliage and glandular-serrate sepals. In these, the anthers are pink to red and the pomes large, oblong-orbicular, and red. The young leaves are densely short, scabrous hairy adaxially when young. (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 | ||
Name authority | Nuttall: in J. Torrey and A. Gray, Fl. N. Amer. 1: 464. (1840) | Sargent: Proc. Rochester Acad. Sci. 4: 97. (1903) |
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