subfamilies

Appelhans, Marc S., Bayly, Michael J., Heslewood, Margaret M., Groppo, Milton, Verboom, G. Anthony, Forster, Paul I., Kallunki, Jacquelyn A. & Duretto, Marco F., 2021, A new subfamily classification of the Citrus family (Rutaceae) based on six nuclear and plastid markers, TAXON 70 (5), pp. 1035-1061 : 1050

Key to subfamilies

The following key summarizes the subfamily classification and provides distinguishing morphological characters:

1. Gynoecium unicarpellate; androecium diplostemonous; leaves simple or pinnate; confined to the Americas…… ………………………………………… Amyridoideae

1. Gynoecium of more than one carpel; if gynoecium unicarpellate then androecium haplostemonous ( Empleurum ; S Africa), or leaves digitate ( Vepris ; Africa-Madagascar to India); androecium haplo-, diplo- or polystemonous; leaves simple, pinnate or digitate; nearly cosmopolitan……………………………………………2

2. Fruit syncarpous and baccate (either a typical berry or a hesperidium), sometimes with a woody or leathery pericarp; seeds lacking endosperm; androecium diplo- or polystemonous (sometimes haplostemonous in Glycosmis )………………………………… Aurantioideae

2. Fruit apocarpous or syncarpous, mostly capsular, follicular, drupaceous or samaroid, if baccate, then seeds with endosperm ( Hortia ) or androecium haplostemonous ( Casimiroa ); seeds with or without endosperm; androecium haplo- or diplostemonous………………………3

3. Perennial herbs or subshrubs with actinomorphic flowers (most taxa) or trees with loculicidal capsule with a central axis, winged seeds and 6–8 ovules per locule ( Chloroxylon )…………………………………………4

3. Trees or shrubs with actinomorphic or zygomorphic flowers; rarely herbs with zygomorphic flowers ( Dictamnus , Ertela ) or with 1 or 2 ovules per locule ( Boronia , Cyanothamnus); fruit not a loculicidal capsule with a central axis and winged seeds…………………………5

4. Leaves simple (rarely 3- to 5-parted/divided); flowers 5-merous; staminal filaments bearded within; ovules (1) 2–4(–8) per locule………………… Haplophylloideae 4. Leaves usually 3-foliate, pinnate or deeply and/or compoundly lobed, rarely simple ( Thamnosma ) and then flowers 4-merous; flowers 4(5)-merous; staminal filaments not bearded within; ovules 4 to several per locule…… ……………………………………………… Rutoideae

5. Secretory cavities in leaves absent or confined to leaf margin; staminal filaments often appendaged ( Dictyoloma , Harrisonia , Sohnreyia , Spathelia )…………… ………………………………………… Cneoroideae

5. Secretory cavities usually present throughout leaves and other parts of the plant; staminal filaments not appendaged………………………………… Zanthoxyloideae