Crataegus rivularis |
Crataegus dispar |
|
---|---|---|
mountain river hawthorn, river hawthorn |
aiken hawthorn |
|
Habit | Shrubs or trees, 30–50 dm. | Shrubs or trees, 50 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. |
ultimate twigs relatively stout; twigs: new growth densely appressed-canescent, 2–3-years old dark gray or gray-brown; thorns on twigs absent or numerous, straight, 2-years old purple-brown, slender, 3–4 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 length 20–35% blade, densely appressed-hairy young, glandular; blade ± obovate-spatulate, 2.3–3.5 cm, thin, base gradually tapered, lobes 2 per side, subterminal, sinuses shallow (LII 15–20%), lobe apex acute, margins glandular-serrate, veins 2 or 3 per side, apex acuminate, abaxial surface ± persistently pubescent, adaxial densely tomentose, ± glabrate. |
Inflorescences | 6–12-flowered; branches glandular-punctate; bracteoles early caducous, usually present, margins sessile-glandular. |
2–4-flowered; branches densely appressed-pubescent; bracteoles deciduous, linear, margins glandular, adaxially short-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. |
13–16 mm diam.; hypanthium densely pubescent; sepals narrow, 3 mm, margins glandular-serrate, abaxially pubescent; anthers ivory; styles 4 or 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. |
bright orange-red or reddish, orbicular, 8–12 mm diam., glabrate to slightly pubescent; sepals reflexed; pyrenes 4 or 5. |
Crataegus rivularis |
Crataegus dispar |
|
Phenology | Flowering mid May–early Jun; fruiting Aug–Sep. | Flowering Mar–Apr; fruiting Jul–Aug. |
Habitat | Intermontane streamsides, ditches, flood plains | Brush, sandy soil |
Elevation | 1300–2300 m (4300–7500 ft) | 30–100 m (100–300 ft) |
Distribution |
AZ; CO; ID; NM; NV; UT; WY
|
AL; FL; GA; 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 dispar is a somewhat scarce species, concentrated in South Carolina and with scattered records from Alabama, Florida, and Georgia. The author notes the species in South Carolina grows in extremely dry conditions. Crataegus dispar is one of the most easily recognized members of ser. Lacrimatae, even identifiable in specimens lacking reproductive parts and sometimes from extension shoots alone. Of note are the wide extension-shoot leaves, often deeply incised into wide-spreading, sharp segments lobed nearly to the sinuses, rather as in C. marshallii. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 510. | FNA vol. 9, p. 632. |
Parent taxa | Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Douglasia > ser. Cerrones | Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Coccineae > ser. Lacrimatae |
Sibling taxa | ||
Name authority | Nuttall: in J. Torrey and A. Gray, Fl. N. Amer. 1: 464. (1840) | Beadle: Biltmore Bot. Stud. 1: 28. (1901) |
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