Maloideae

The Maloideae C.Weber are the apple subfamily, a grouping used by some taxonomists within the rose family, Rosaceae. Recent molecular phylogenetic evidence^[1] has shown that the traditional Spiraeoideae and Amygdaloideae form part of the same clade as the traditional Maloideae, and the correct name for this group is Amygdaloideae. Earlier circumscriptions of Maloideae are more-or-less equivalent to subtribe Malinae or to tribe Maleae. The group includes a number of plants bearing commercially important fruits, such as apples and pears, while others are cultivated as ornamentals.

In its traditional circumscription^[2] this subfamily consisted exclusively of shrubs and small trees characterised by a pome, a type of accessory fruit that does not occur in other Rosaceae, and by a basal haploid chromosome count of 17 (instead of 7, 8, or 9 as in the other Rosaceae), involving approximately 28 genera with approximately 1100 species worldwide, with most species occurring in the temperate Northern Hemisphere.

Taxonomy

The subfamily was given the name Pomoideae Juss. in 1789, but this name is no longer accepted under the nomenclature codes because it is not based on a genus name. It has also been separated into its own family the Malaceae Small^[3] (formerly Pomaceae Lindl.).^[4]

Recent molecular data have shown that the traditional subfamily Spiraeoideae is paraphyletic,^[5][1] and to best reflect relationships subfamily Amygdaloideae has been expanded to include the former Spiraeoideae and Maloideae.^[1]

An earlier intermediate classification^[6] expanded Maloideae to include four genera with dry non-pome fruit. These are Kageneckia, Lindleya, and Vauquelinia, which have a haploid chromosome count of 15 or 17, and Gillenia, which is herbaceous and has a haploid chromosome count of 9.

A traditional circumscription of Maloideae includes the following genera:^[2]
Amelanchier - serviceberry, juneberry
Aria (see Sorbus)
Aronia - chokeberry
Chaenomeles - Japanese quince
Chamaemeles
Chamaemespilus (see Sorbus chamaemespilus)
Cormus (see Sorbus)
Cotoneaster - cotoneaster
Crataegus - hawthorn
Cydonia - quince
Dichotomanthes
Docynia
Docyniopsis
Eriobotrya - loquat
Eriolobus
Hesperomeles
Heteromeles - toyon
Malacomeles
Malus - apple, crabapple
Mespilus - medlar
Osteomeles
Peraphyllum
Photinia
Pseudocydonia - Chinese quince
Pyracantha - firethorn
Pyrus - pear
Rhaphiolepis - hawthorn
Sorbus - rowan, whitebeam, service tree
Stranvaesia = Photinia pro parte
Torminalis (see Sorbus torminalis)

intergeneric hybrids^[7]:
×Amelasorbus
×Crataegosorbus
×Crataemespilus
×Malosorbus
×Sorbocotoneaster
×Sorbopyrus

and graft hybrids:
+Crataegomespilus
+Pyrocydonia (Pirocydonia)

Notes

1. ^ ^{a b c} 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. doi:10.1007/s00606-007-0539-9
2. ^ ^{a b} 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
3. ^ GRIN Taxonomy for Plants
4. ^ Lindley, J. (1822). Observations on the natural group of plants called Pomaceae. Transactions of the Linnean Society of London. 13: 88–106.
5. ^ Morgan, D.R.; Soltis, D.E.; Robertson, K.R. (1994). Systematic and evolutionary implications of rbcL sequence variation in Rosaceae. American Journal of Botany. 81(7): 890–903.
6. ^ Evans, R. C., Campbell, C. S. (2002). "The origin of the apple subfamily (Maloideae; Rosaceae) is clarified by DNA sequence data from duplicated GBSSI genes". American Journal of Botany 89 (9): 1478–1484. doi:10.3732/ajb.89.9.1478. PMID 21665749. 
7. ^ Stace, C.A. 1975. Hybridization and the flora of the British Isles. Academic Press, London.

References

• Joseph R. Rohrer, Kenneth R. Robinson, James B. Phipps - Floral Morphology of Maloideae (Rosaceae) and its systematic Relevance; American Journal of Botany, 81 (5), P. 574-581; 1994