Genera included in this tribe:
Buddleja; Emorya; Gomphostigma.
The genera Polypremum (Tetrachondraceae) and Peltanthera (Peltantheraceae), historically considered as members of the tribe, are now known to be unrelated to Buddleja.
Molecular data (Chau et al 2017) suggests the genera Emorya and Gomphostigma are members of a monophyletic genus Buddleja, and therefore renamed Emorya suaveolans as Buddleja normaniae, and returned Gomphostigma virgatum to its original Linnean name of Buddleja virgata. The species correlate phylogenetically with their location, and they can be grouped by continent: Asia, Africa, and the Americas.
Buddleja species were divided into four sections by Leeuwenberg (1979):
SECTION: Buddleja: New World species distinguished by a valvate corolla e.g.: B. americana.
SECTION: Chilianthus: African species with anthers that protrude beyond the corolla e.g.: B. saligna.
SECTION: Neemda: the majority of species from all continents.
SECTION: Nicodemia: African species, mainly from Madagascar, distinguised by forming an indehiscent berry rather than a dry (dehiscent) seed capsule e.g.: B. madagascariensis.
Marquand (1930) divided the Old World Buddleja into four series: Alternifoliae, Curviflorae, Rectiflorae and Gynandrae; this last series was based only on a single atypical specimen of B. paniculata (syn. B. gynandra). Leeuwenberg (1979) did not maintain these series, as he believed the Asian species to be continuous. They are used here for convenience.
Series 1: Alternifoliae - alternate rather than opposite leaves. Diploid (2n=2x=38).
Series 2: Curviflorae - curved corolla tube. Diploid (2n=2x=38).
Series 3: Rectiflorae (incorporating Gynandrae) - straight corolla tube.
These species can be crudely divided by their ploidy level.
Hexaploid and dodecaploid (2n=6x=114 and 2n=12x=228).
Some B. nivea (notably var. yunannensis) and B. macrostachya specimens are dodecaploid, but it is not known whether this represents nascent speciation in isolated populations.
Buddleja delavayi (formerly B. heliophila)
Buddleja limitanea (sunk under B. forrestii by Leeuwenberg)
Buddleja stenostachya (sunk under B. nivea by Leeuwenberg)
Buddleja nivea var. yunnanensis (sunk under B. nivea by Leeuwenberg)
Variable high level polyploidy (2n=8x-24x=152-456).
Naturally Occuring Hybrids
These are frequently between plants of the same ploidy.
Most are species formerly assigned to the genus Nicodemia.
Some authorities consider this section represents a separate genus (Chilianthus).
Gomphostigma virgatum = Buddleja virgata
Gomphostigma incomptum = Buddleja incompta
The Leeuwenberg (1979) sections: Buddleja and Neemda
were combined by Norman (2000) and then divided into 12 series.
Genus Emorya included in Buddleja.
Series 1: Thyrsoides
Series 2: Oblongae
Series 3: Stachyoides
Series 4: Globosae
Series 5: Anchoenses
Series 6: Glomeratae
Series 7: Brachiatae
Series 8: Lanatae
Series 9: Scordiodes
Series 10: Buddleja (= Leeuwenberg's Section: Buddleja)
Series 11: Verticillatae
Series 12: Cordatae
Emorya suaveolans = Buddleja normaniae
Emorya rinconensis = Buddleja rinconensis
Chau, J., O'Leary, N., Weibang Sun, Olmstead, R. (2017). Phylogenetic relationships in tribe Buddlejeae (Scrophulariaceae) based on multiple nuclear and plastid markers. Botanical Journal of the Linnean Society. 184. 137-166.
Gao Chen, Weibang Sun, Hang Sun. (2007) Ploidy variation in Buddleja L. (Buddlejaceae) in the Sino-Himalayan region and its bio-geographical implications. Botanical Journal of the Linnean Society 154 pages 305-312.
Leeuwenberg, A.J.M. (1979) The Loganiaceae of Africa XVIII Buddleja L. II, Revision of the African & Asiatic species. H. Veenman & Zonen B. V., Wageningen, Netherlands.
Li, P. T. (1982) A study on the genus Buddleja L. of China. Acta Bot. Yunnanica 4 (3): 227-240.
Marquand C.V.B. (1930). Revision of the old world species of Buddleja. Kew Bulletin 1930: 177-208.
Moore, R.J. (1960). Cytotaxonomic notes on Buddleia. L. Am. J. Bot. 47:511-517.
Norman, E.M. (2000). Buddlejaceae. Flora Neotropica 81. New York Botanical Garden, USA.