There are 42 accepted species of flowering plants in the genus Dahlia, according to The Plant List.[1] The sectional classification of Dahlia sensu Sørensen (1969)[2] as updated by Saar et al. (2003)[3] and Hansen (2004)[4] and (2008)[5] is as follows (excluding infraspecific taxa);
^ abcdefghijklmnopqSchie, Stephan; Debener, Thomas (2013-02-05). "The generation of novel species hybrids between garden dahlias andDahlia macdougalliito increase the gene pool for variety breeding". Plant Breeding. 132 (2). Wiley: 224–228. doi:10.1111/pbr.12034. ISSN0179-9541.
^Elevated from D. dissecta var. sublignosa but still listed as unresolved in The Plant List
^REYES-SANTIAGO, JERÓNIMO; ISLAS-LUNA, MARÍA DE LOS ÁNGELES; MACÍAS-FLORES, RAFAEL GUADALUPE; CASTRO-CASTRO, ARTURO (2018-05-15). "Dahlia tamaulipana (Asteraceae, Coreopsideae), a new species from the Sierra Madre Oriental biogeographic province in Mexico". Phytotaxa. 349 (3). Magnolia Press: 214. doi:10.11646/phytotaxa.349.3.2. ISSN1179-3163.
^Accepted name in The Plant List, but was not accepted by Saar (2003). Hansen, H. V. and J. P. Hierting. 1996. Observations on chromosome numbers and biosystematics in Dahlia (Asteraceae, Heliantheae) with an account on the identity of D. pinnata, D.rosea and D. coccinea. Nordic Journal of Botany 16: 445-455.
^Castro-Castro, Arturo; Munguía-Lino, Guadalupe; Islas-Luna, María De Los Ángeles; Reyes-Santiago, Jerónimo (2019-03-01). "Dahlia mixtecana (Asteraceae, Coreopsideae), a striking new species from Oaxaca, Mexico". Phytotaxa. 394 (3): 209–218. doi:10.11646/phytotaxa.394.3.2. ISSN1179-3163. S2CID91968889.