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Washington hawthorn, Washington thorn

Habit Trees, 40–100 dm. Trees, 55 dm.
Stems

3-year old twigs shiny, deep reddish brown, older dark gray;

thorns on twigs ± straight, 2–5 cm.

twigs: new growth canescent, 1-year old dark brown, older gray;

thorns on twigs absent or few, straight or slightly curved, 1-year old dark purple, 3 cm.

Leaves

petiole slender, sometimes both abaxially and adaxially short rusty-tomentose, eglandular;

blade broadly to narrowly deltate, 3–6 cm, base truncate to rarely cuneate or cordate, sometimes very shallowly so, lobes palmately or pinnately 2(or 3) per side, margins serrulate, veins 6 or 7(or 8) per side (to sinuses), apex acute, surfaces glabrous.

deciduous;

petiole slender, length 33–43% blade, distally winged, densely pubescent, eglandular;

blade elliptic to suborbiculate, 3–7 cm, base cuneate, lobes 0 or 1–3 per side, apiculi, margins sharply serrate, venation craspedodromous, veins 5 per side, sharply impressed, apex acute, surfaces glabrate, glabrescent, abaxial veins densely pubescent, adaxial appressed-pubescent young.

Inflorescences

15–30-flowered, flowers strong-smelling;

branches glabrous;

bracteole margins stipitate-glandular.

10–20-flowered;

branches tomentose;

bracteoles caducous, numerous, linear, ± membranous, margins glandular.

Flowers

10–12 mm diam.;

hypanthium glabrous;

sepals 2 mm;

stamens 20, anthers ivory;

styles 3(or 4).

20–25 mm diam.;

hypanthium canescent;

sepals narrowly triangular, margins glandular-serrate to glandular-laciniate, abaxial surface densely pubescent;

stamens 20, anthers cream, sometimes pink;

styles 4 or 5.

Pomes

crimson, suborbicular, 12–17 mm diam., pubescent;

sepals erose or patent;

pyrenes 4 or 5, dorsally grooved, sides plane.

2n

= 51, 68.

Crataegus phaenopyrum

Crataegus ×dispessa

Phenology Flowering Jun; fruiting Sep–Nov. Flowering May; fruiting Sep–Oct.
Habitat Woodland edges, gaps, scrub, damp locations Brush, along streams and woodland margins
Elevation 10–300 m (0–1000 ft) 100–200 m (300–700 ft)
Distribution
from FNA
AR; DE; FL; GA; IL; IN; KY; LA; MD; MI; MO; MS; NC; OH; OR; PA; SC; TN; VA; WA; WV; ON
[WildflowerSearch map]
[BONAP county map]
from FNA
MO
Discussion

Crataegus phaenopyrum has a wide native range across the middle latitudes of the United States from Missouri to Maryland and southward but is not particularly abundant. In the northern and western states and Ontario, it is introduced. All alleged specimens for Alabama proved to be wrongly identified (J. B. Phipps 1998).

The flowering season of the Washington thorn is the latest of all North American hawthorns. The species is one of the most widely planted ornamentals in the genus, being elegantly treelike and possessing beautiful, remarkably rust-resistant foliage at all seasons as well as attractive flowers and fruit. Several cultivars are known.

Crataegus cordata (Miller) Aiton 1789 (= Mespilus cordata Miller 1757) was commonly used for C. phaenopyrum until the early 20th century (J. B. Phipps 1999).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Crataegus ×dispessa is found in southern Missouri to Boone County and was last collected in Dallas County.

Crataegus ×dispessa is probably of ser. Molles × C. collina var. hirtiflora parentage, the bracteole type not being characteristic of ser. Molles.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 9, p. 499. FNA vol. 9, p. 638.
Parent taxa Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus > sect. Crataegus > ser. Cordatae Rosaceae > subfam. Amygdaloideae > tribe Maleae > Crataegus
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. 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. 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. 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. ×fretalis, C. ×incaedua, C. ×kelloggii, C. ×latebrosa, C. ×lucorum, C. ×rufula, C. ×sicca, C. ×vailiae
Synonyms Mespilus phaenopyrum, C. youngii C. pyriformis, C. treleasei
Name authority (Linnaeus f.) Medikus: Gesch. Bot., 84. (1793) Crataegus ×dispessa Ashe: J. Elisha Mitchell Sci. Soc. 19: 17. (1903) — as species
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