Maleae Explained

The Maleae (incorrectly Pyreae) are the apple tribe in the rose family, Rosaceae. The group includes a number of plants bearing commercially important fruits, such as apples and pears, while others are cultivated as ornamentals. Older taxonomies separated some of this group as tribe Crataegeae,^{[1] [2]} as the Cydonia group (a tentative placement),^[2] or some genera were placed in family Quillajaceae.^[2]

The tribe consists exclusively of shrubs and small trees. Most have pomes, a type of accessory fruit that does not occur in other Rosaceae. All except Vauquelinia (with 15 chromosomes) have a basal haploid chromosome count of 17, instead of 7, 8, or 9 as in the other Rosaceae.^[3]

There are approximately 28 genera that contain about 1100 species worldwide, with most species occurring in the temperate Northern Hemisphere.

Current classification

Core members of the group

A traditional circumscription of Maleae includes the following genera:^{[1] [2] [4] [5]}

• Amelanchier - serviceberry, juneberry, saskatoon, sugarplum
• Aria - whitebeam
• Aronia - chokeberry
• Chaenomeles - Japanese quince
• Chamaemeles
• Chamaemespilus - false medlar
• Cormus - service tree
• Cydonia - quince
• Dichotomanthes
• Docynia
• Docyniopsis
• Eriobotrya -loquat
• Eriolobus
• Hesperomeles
• Heteromeles - toyon
• Malacomeles - false serviceberry
• Malus - apple, crabapple
• Osteomeles
• Peraphyllum - wild crab apple, squaw apple
• Phippsiomeles^[6]
• Photinia
• Pourthiaea^[6]
• Pseudocydonia - Chinese quince
• Pyrus - pear
• Rhaphiolepis - hawthorn
• Sorbus (s.s.) - rowan
• Stranvaesia^[6]
• Torminalis - chequer tree

intergeneric hybrids:^{[7] [8]}

• × Amelasorbus
• × Malosorbus
• × Sorbaronia
• × Sorbopyrus

and graft chimeras:
+ Pyrocydonia (Pirocydonia)

Tribe Crataegeae

A recent taxonomic treatment includes the following genera in Maleae that were earlier separated as tribe Crataegeae (or as intertribe hybrids):^[9]

• Cotoneaster - cotoneaster
• Crataegus - hawthorn
• Mespilus - medlar
• Pyracantha - firethorn

intergeneric (including intertribal) hybrids:^[7]

• × Crataemespilus
• × Crataegosorbus
• × Sorbocotoneaster

and the graft hybrid:

• + Crataegomespilus

Former members of family Quillajaceae

The following genera were previously placed in tribe Quillajeae in Rosaceae, or in family Quillajaceae. Their fruit are dry capsules, not pomes.

• Kageneckia
• Vauquelinia
• Lindleya

The Cydonia group

The Cydonia group within the Maloid Rosaceae was a tentative grouping of pome-fruited genera with many ovules (rather than just two) per carpel.^[2] The genera involved were:

• Cydonia
• Chaenomeles
• Docynia
• Pseudocydonia

It is not yet clear whether this group is monophyletic within the Maleae. Molecular data indicate a close relationship between Cydonia and Pseudocydonia.^[5] Multiple ovules per carpel also occur in Kageneckia, a non-pome-bearing genus.^[5] Chloroplast DNA analysis, but not nuclear DNA, shows a tight relationship between Cydonia and Dichotomanthes, a non-pome-bearing genus.^[5]

Notes and References

1. G. K. Schulze-Menz 1964. Reihe Rosales. in A. Engler's Syllabus der Pflanzenfamilien mit besonderer Berücksichtigung der Nutzpflanzen nebst einer Übersicht über die Florenreiche und Florengebiete der Erde, Gebrüder Borntraeger, Berlin
2. Book: Kalkman, C. . 2004 . Flowering plants, dicotyledons : Celastrales, Oxalidales, Rosales, Cornales, Ericales . Rosaceae . Springer . Berlin . K. Kubitzki . 343–386. 6.
3. Goldblatt, P. . 1976 . Cytotaxonomic studies in the tribe Quillajeae (Rosaceae) . Annals of the Missouri Botanical Garden . 63 . 1 . 200–206 . 10.2307/2395226. 2395226 .
4. Sterling, C. . 1965 . Comparative morphology of the carpel in the Rosaceae. V. Pomoideae: Amelanchier, Aronia, Malacomeles, Malus, Peraphyllum, Pyrus, Sorbus . American Journal of Botany . 52 . 4 . 418–426 . 10.2307/2440337. 2440337 .
5. Campbell, C.S. . Evans, R.C. . Morgan, D.R. . Dickinson, T.A. . Arsenault, M.P. . 2007 . Phylogeny of subtribe Pyrinae (formerly the Maloideae, Rosaceae): Limited resolution of a complex evolutionary history . Plant Systematics and Evolution . 266 . 1–2 . 119–145 . 10.1007/s00606-007-0545-y.
6. Liu . B.B. . Hong . D.Y. . Zhou . S.L. . Xu . C. . Dong . W.P. . Johnson . G. . Wen . J. . 2019 . Phylogenomic analyses of the Photinia complex support the recognition of a new genus Phippsiomeles and the resurrection of a redefined Stranvaesia in Maleae (Rosaceae) . Journal of Systematics and Evolution . 57 . 6 . 678–694 . 10.1111/jse.12542. free .
7. [Stace, C. A.]
8. Web site: USDA PLANTS.
9. Potter, D.; Eriksson, T.; Evans, R.C.; Oh, S.H.; Smedmark, J.E.E.; Morgan, D.R.; Kerr, M.; Robertson, K.R.; Arsenault, M.P.; Dickinson, T.A.; Campbell, C.S. (2007). Phylogeny and classification of Rosaceae. Plant Systematics and Evolution. 266(1–2): 5–43.