Crataegus rivularis |
Crataegus phippsii |
|
---|---|---|
mountain river hawthorn, river hawthorn |
Phipps' hawthorn |
|
Habit | Shrubs or trees, 30–50 dm. | Shrubs or trees, 50–60(–70) 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. |
main trunk usually present, sometimes suckering; twigs: new growth densely short-pubescent, 1-year old dark purple-brown, older dark gray; thorns on twigs few, slightly recurved, deep brown to black, ± slender, 2–4 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 1.5–2 cm, hairy, glandularity not recorded; blade broadly elliptic to ovate or broadly deltate-ovate, 4–8 cm (–10 cm on extension shoots), becoming ± coriaceous, base cuneate to very broadly cuneate, lobes 3 per side, sinuses ± shallow, lobe apex rounded to broadly angled, margins short-serrate, veins 4(or 5) per side, apex obtuse or subacute, abaxial surface subglabrous or glabrescent, veins persistently short-hairy, adaxial short-appressed-hairy. |
Inflorescences | 6–12-flowered; branches glandular-punctate; bracteoles early caducous, usually present, margins sessile-glandular. |
6–12-flowered; branches densely short-tomentose; bracteole margins stipitate- or sessile-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. |
15–22 mm diam.; hypanthium densely tomentose, disc interior glabrous, bristly at center; sepals broadly triangular, 4–5 mm, margins glandular-serrate, apex subacute, abaxially pubescent (especially near base); stamens 10, anthers pale pink; styles 2–4, stigmas capitate. |
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 to plum purple (Aug) to nearly black (Sep), ± orbicular to broadly ovoid, 12 mm diam., short-pubescent; sepals erect-patent to patent-incurved, 4–5 mm; pyrenes 3, sides irregularly eroded or ± plane. |
2n | = 68. |
|
Crataegus rivularis |
Crataegus phippsii |
|
Phenology | Flowering mid May–early Jun; fruiting Aug–Sep. | Flowering May; fruiting Sep–Oct. |
Habitat | Intermontane streamsides, ditches, flood plains | Brush, natural hedgerows on mesic soil |
Elevation | 1300–2300 m (4300–7500 ft) | 300–700 m (1000–2300 ft) |
Distribution |
AZ; CO; ID; NM; NV; UT; WY
|
MT; WA; BC |
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 phippsii is found from the Okanagan Valley, southern British Columbia and northwestern Washington, to near Flathead Lake, Montana. Crataegus phippsii is one of the more distinctive North American hawthorns and does not appear to be closely similar to any other known in the west. The plants are large, somewhat reminiscent of C. mollis in foliage, habit, and pubescence; in its fruit (red changing to purple to black) there is a color change similar to those in other species in this series. The bracteoles are smaller than in the mollis group, caducous and membranous, and bright crimson when fresh. The light gray bark flakes off in long narrow strips, which is unusual in Crataegus. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 510. | FNA vol. 9, p. 508. |
Parent taxa | Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Douglasia > ser. Cerrones | Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Douglasia > ser. Purpureofructus |
Sibling taxa | ||
Name authority | Nuttall: in J. Torrey and A. Gray, Fl. N. Amer. 1: 464. (1840) | O'Kennon: Sida 18: 185, figs. 7, 9a–c. (1998) |
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