Flora of North America species comparison

The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Crataegus rivularis

Crataegus sheridana

mountain river hawthorn, river hawthorn

Great Plains hawthorn
Habit Shrubs or trees, 30–50 dm. Shrubs, 20–35 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 color not recorded, pubescent, 1-year old light brown to olive-tan or mid brown, 2-years old dark gray or reddish brown overlaid dark gray, older gray;

thorns on twigs usually numerous, usually recurved, 2-years old very dark, shiny red-brown, slender to moderately thick, (2.5–)3–5(–7) 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 40–50% blade, pubescent (especially in adaxial sulcus), ± densely sessile-glandular;

blade sometimes broadly ovate or suborbiculate, sometimes ± ovate, elliptic-ovate to ovate, 3.5–5(–6) cm, nearly full grown at flowering, ± thin, base cuneate, broadly cuneate, or subtruncate to subcordate, lobes (3 or)4(or 5) per side, sinuses shallow, LII 5–15%, lobe apex acute (except where blades elliptic-ovate to ovate, then lobes deeper, LII 15–30%, lobe apex subacute), margins with subacute teeth, veins 3 or 4 per side, apex acute to obtuse, abaxial surface glabrous, veins glabrous or pubescent young, adaxial densely appressed-scabrous-pubescent young (variably persistent).
Inflorescences

6–12-flowered;

branches glandular-punctate;

bracteoles early caducous, usually present, margins sessile-glandular.

5–15-flowered;

branches ± densely pubescent;

bracteoles pallid, narrow, margins 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.

14–16 mm diam.;

hypanthium proximally ± tomentose, medially densely short-pubescent;

sepals greenish, triangular, length not recorded, margins glandular-serrate, abaxially glabrous, adaxially pubescent;

stamens 10, 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.

1–6 in infructescences, bright red, broadly ellipsoid to suborbicular, 9–11 mm tall, pubescent, rarely glabrate;

sepals ± spreading to reflexed;

pyrenes 3 or 4, sides ± roughened with shallow, irregular pitting or diagonal scarring.

Crataegus rivularis

Crataegus sheridana
Phenology Flowering mid May–early Jun; fruiting Aug–Sep. Flowering May–Jun; fruiting Sep.
Habitat Intermontane streamsides, ditches, flood plains Thickets, brush
Elevation 1300–2300 m (4300–7500 ft) 300–1200 m (1000–3900 ft)
Distribution
from FNA
AZ; CO; ID; NM; NV; UT; WY
[WildflowerSearch map]
[BONAP county map]
from FNA
MN; MT; ND; SD; WY; AB; SK
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 sheridana occurs only east of the Rocky Mountains and is abundant in the Cypress Hills of Alberta and Saskatchewan. Collections from the montane islands of Montana are also known. Until confusion with the superficially similar C. chrysocarpa of the Great Plains and Prairies is cleared up in all the relevant herbaria, we will have an incomplete knowledge of the distribution of C. sheridana; however, it is widespread in the Great Plains region. Its plants are usually taller than sympatric C. chrysocarpa and also C. macracantha.

Crataegus sheridana has superficial resemblances to the C. chrysocarpa group; it is distinguished by its pitted pyrenes and usually larger leaves. In the Cypress Hills, where this species has the shortest thorns of any hawthorn in the red-fruited group, it is further distinguished from most specimens of the C. chrysocarpa group by the densely hairy to tomentose inflorescence branches and hypanthia and by its leaf shape. Collections from the Cypress Hills indicate that form of C. sheridana to be peculiarly round-leaved with pallid bracteoles; Montana forms have longer thorns, longer, more acutely lobed leaves, more elliptic-ovate to ovate blades, and red-brown rather than pallid bracteoles.

In all likelihood, Crataegus sheridana represents a series of hybrid descendants between C. chrysocarpa and C. macracantha. The reasons for ignoring its existence over a long period were discussed by J. B. Phipps et al. (2007).

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Source FNA vol. 9, p. 510. FNA vol. 9, p. 521.
Parent taxa Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Douglasia > ser. Cerrones Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Macracanthae > ser. Macracanthae
Sibling taxa
C. aemula, C. aestivalis, C. alabamensis, C. alleghaniensis, C. annosa, C. aprica, C. aquacervensis, C. ashei, C. atrovirens, C. attrita, C. austromontana, C. beata, C. berberifolia, C. biltmoreana, C. brachyacantha, C. brainerdii, C. brazoria, C. brittonii, C. buckleyi, C. calpodendron, C. castlegarensis, C. chrysocarpa, C. coccinea, C. coccinioides, C. cognata, C. collina, C. colonica, C. communis, C. compacta, C. condigna, C. craytonii, C. crocea, C. crus-galli, C. cupressocollina, C. delawarensis, C. dispar, C. dodgei, C. douglasii, C. egens, C. egregia, C. enderbyensis, C. erythropoda, C. exilis, C. eximia, C. extraria, C. fecunda, C. flabellata, C. flava, C. florens, C. floridana, C. florifera, C. fluviatilis, C. formosa, C. frugiferens, C. furtiva, C. gattingeri, C. gaylussacia, C. gilva, C. greggiana, C. harbisonii, C. holmesiana, C. ignava, C. incilis, C. integra, C. intricata, C. invicta, C. iracunda, C. irrasa, C. jesupii, C. jonesiae, C. lacrimata, C. laevigata, C. lanata, C. lancei, C. lanuginosa, C. lassa, C. laurentiana, C. leonensis, C. lepida, C. levis, C. lumaria, C. macracantha, C. macrosperma, C. magniflora, C. margarettae, C. marshallii, C. mendosa, C. meridiana, C. mira, C. mollis, C. monogyna, C. munda, C. nananixonii, C. neobushii, C. nitida, C. oakesiana, C. okanaganensis, C. okennonii, C. opaca, C. opima, C. orbicularis, C. ouachitensis, C. padifolia, C. pennsylvanica, C. persimilis, C. pexa, C. phaenopyrum, C. phippsii, C. pinetorum, C. populnea, C. prona, C. pruinosa, C. pulcherrima, C. punctata, C. purpurella, C. quaesita, C. reverchonii, C. rivuloadamensis, C. rivulopugnensis, C. roribacca, C. rubella, C. rubribracteolata, C. saligna, C. sargentii, C. scabrida, C. schizophylla, C. schuettei, C. segnis, C. senta, C. sheila-phippsiae, C. sheridana, C. shuswapensis, C. sororia, C. spathulata, C. spes-aestatum, C. stolonifera, C. stonei, C. submollis, C. suborbiculata, C. succulenta, C. tecta, C. teres, C. texana, C. tracyi, C. triflora, C. turnerorum, C. uniflora, C. ursopedensis, C. venusta, C. viridis, C. visenda, C. wattiana, C. williamsii, C. wootoniana, C. ×atrorubens, C. ×bicknellii, C. ×coleae, C. ×collicola, C. ×disperma, C. ×dispessa, C. ×fretalis, C. ×incaedua, C. ×kelloggii, C. ×latebrosa, C. ×lucorum, C. ×rufula, C. ×sicca, C. ×vailiae
C. aemula, C. aestivalis, C. alabamensis, C. alleghaniensis, C. annosa, C. aprica, C. aquacervensis, C. ashei, C. atrovirens, C. attrita, C. austromontana, C. beata, C. berberifolia, C. biltmoreana, C. brachyacantha, C. brainerdii, C. brazoria, C. brittonii, C. buckleyi, C. calpodendron, C. castlegarensis, C. chrysocarpa, C. coccinea, C. coccinioides, C. cognata, C. collina, C. colonica, C. communis, C. compacta, C. condigna, C. craytonii, C. crocea, C. crus-galli, C. cupressocollina, C. delawarensis, C. dispar, C. dodgei, C. douglasii, C. egens, C. egregia, C. enderbyensis, C. erythropoda, C. exilis, C. eximia, C. extraria, C. fecunda, C. flabellata, C. flava, C. florens, C. floridana, C. florifera, C. fluviatilis, C. formosa, C. frugiferens, C. furtiva, C. gattingeri, C. gaylussacia, C. gilva, C. greggiana, C. harbisonii, C. holmesiana, C. ignava, C. incilis, C. integra, C. intricata, C. invicta, C. iracunda, C. irrasa, C. jesupii, C. jonesiae, C. lacrimata, C. laevigata, C. lanata, C. lancei, C. lanuginosa, C. lassa, C. laurentiana, C. leonensis, C. lepida, C. levis, C. lumaria, C. macracantha, C. macrosperma, C. magniflora, C. margarettae, C. marshallii, C. mendosa, C. meridiana, C. mira, C. mollis, C. monogyna, C. munda, C. nananixonii, C. neobushii, C. nitida, C. oakesiana, C. okanaganensis, C. okennonii, C. opaca, C. opima, C. orbicularis, C. ouachitensis, C. padifolia, C. pennsylvanica, C. persimilis, C. pexa, C. phaenopyrum, C. phippsii, C. pinetorum, C. populnea, C. prona, C. pruinosa, C. pulcherrima, C. punctata, C. purpurella, C. quaesita, C. reverchonii, C. rivularis, C. rivuloadamensis, C. rivulopugnensis, C. roribacca, C. rubella, C. rubribracteolata, C. saligna, C. sargentii, C. scabrida, C. schizophylla, C. schuettei, C. segnis, C. senta, C. sheila-phippsiae, C. shuswapensis, C. sororia, C. spathulata, C. spes-aestatum, C. stolonifera, C. stonei, C. submollis, C. suborbiculata, C. succulenta, C. tecta, C. teres, C. texana, C. tracyi, C. triflora, C. turnerorum, C. uniflora, C. ursopedensis, C. venusta, C. viridis, C. visenda, C. wattiana, C. williamsii, C. wootoniana, C. ×atrorubens, C. ×bicknellii, C. ×coleae, C. ×collicola, C. ×disperma, C. ×dispessa, C. ×fretalis, C. ×incaedua, C. ×kelloggii, C. ×latebrosa, C. ×lucorum, C. ×rufula, C. ×sicca, C. ×vailiae
Name authority Nuttall: in J. Torrey and A. Gray, Fl. N. Amer. 1: 464. (1840) A. Nelson: Bot. Gaz. 34: 370. (1902)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



Type/paste one or more Latin names into the boxes above; matching taxa will show up below the box as you type. You can use the up/down arrow keys to move through the list.

(If the plant you're looking for doesn't show up in the auto-complete list, that means it either isn't described in Flora of North America yet, or it's listed under a synonym. And please note that Flora of North America is still missing several plant families, including Fabaceae, Apiaceae, Boraginaceae, and Polemoniaceae.)

Choose a data source: Flora of North America

The species comparison tool is brought to you by:
Northwest Wildflowers