Belongs within: Campanulaceae.
Contains: Downingia, Siphocampylus, Cyanea.
Lobelia is a cosmopolitan genus of herbaceous plants with resupinate flowers due to a twisted peduncle. Recent phylogenetic studies have indicated that the genus as commonly recognised is non-monophyletic with a number of other lobelioid genera nested within it. Isotoma has been distinguished by the lack of a slit on the upper side of the corolla tube, and filaments adnate to the corolla tube from its base to above the middle (Black & Robertson 1965).
Characters (Black & Robertson 1965): Herbs; flowers in some species dioecious by sterility of anthers in females and of small ovary in males. Sepals 5; corolla-tube slit to base on upper or posterior side, two upper lobes more deeply separated and forming more or less distinct upper lip, lower lip three-lobed, spreading, two protuberances frequently present in throat below; filaments inserted at base of corolla and often united to each other aboe middle; anthers united in an oblique ring around style; stigma two-lobed, usually with ring of collecting hairs below it and exserted beyond anthers in female or bisexual flowers; ovary two-celled; capsule opening at summit loculicidally in two valves.
<==Lobelia Linnaeus 1753 [incl. Colensoa Hooker 1853]A61
|--+--L. borneensisCM16 [=Pratia borneensisP88]
| `--+--+--L. heterophyllaCM16
| | `--L. physaloides Cunn. 1839CM16, A61 (see below for synonymy)
| `--+--+--L. baumanniiCM16
| | `--L. hartlaubiiCM16
| `--+--+--L. malowensisCM16
| | `--L. patulaCM16
| `--+--L. coronopifoliaCM16
| `--+--L. holstiiCM16
| `--L. tomentosaCM16
`--+--+--+--L. thermalisCM16
| | `--+--Grammatotheca bergianaCM16
| | `--+--L. aquaticaCM16
| | `--L. zeylanicaCM16
| `--+--L. linearisCM16
| `--MonopsisCM16
| |--+--M. albaCM16
| | `--M. stellarioidesCM16
| | |--M. s. ssp. stellarioidesB06
| | `--M. s. ssp. schimperianaB06
| `--+--M. debilisCM16
| `--M. flavaCM16
`--+--L. sonderianaCM16
`--+--L. galpiniiCM16
`--+--+--L. laxaCM16
| `--+--L. erinusCM16
| `--+--L. fervensCM16
| `--L. graniticolaCM16
`--+--+--L. anceps Linnaeus 1781CM16, BR65
| `--Wimmerella hederaceaCM16
`--+--L. jasionoidesCM16
`--+--L. urensCM16
`--+--+--DowningiaCM16
| `--SolenopsisCM16
| |--S. antiphonitisCM16
| |--S. laurentiaCM16
| `--S. minutaCM16
`--+--+--+--Diastatea micranthaCM16
| | `--+--Palmerella debilisCM16
| | `--+--L. organensisCM16
| | `--L. petiolataCM16
| `--+--+--+--L. inflataCM16
| | | `--L. kalmiiCM16
| | `--+--L. spicataCM16
| | `--+--L. dortmannaCM16
| | `--+--L. puberulaCM16
| | `--+--L. cardinalisCM16
| | | |--L. c. ssp. cardinalisH93
| | | `--L. c. ssp. gramineaH93
| | | |--L. c. ssp. g. var. gramineaH93
| | | |--L. c. ssp. g. var. multifloraH93
| | | `--L. c. ssp. g. var. pseudosplendensH93
| | `--L. siphiliticaCM16
| `--+--+--L. laxifloraCM16
| | `--+--L. irasuensisCM16
| | `--L. xalapensisCM16
| `--+--L. portoricensisCM16
| `--+--L. kraussiCM16
| `--+--Hippobroma longifloraCM16
| `--+--L. martagonCM16
| `--L. strictaCM16
`--+--+--+--SiphocampylusCM16
| | `--+--L. polyphyllaCM16
| | `--+--L. bridgesiiCM16
| | `--+--L. excelsaCM16
| | `--L. tupaCM16
| `--+--L. angulata Forster 1786CM16, A61 (see below for synonymy)
| `--+--+--+--L. nummulariaCM16
| | | `--L. oligophyllaCM16
| | `--+--L. linnaeoides (Hooker) Petrie 1891 (see below for synonymy)A61
| | `--+--L. macrodonCM16
| | `--L. roughii Hooker 1864CM16, A61 (see below for synonymy)
| `--+--L. chinensisCM16
| `--+--‘Isotoma’ axillarisCM16
| `--+--+--L. arnhemiacaCM16
| | `--L. purpurascensCM16 [=Pratia purpurascens (Brown) Wimmer 1953BR65]
| `--+--L. loochooensisCM16
| `--IsotomaCM16
| |--I. fluviatilis Mueller 1869CM16, BR65 (see below for synonymy)
| |--I. hypocrateriformisOS04
| |--I. petraea Mueller 1852 (see below for synonymy)BR65
| `--I. scapigera Don 1834 (see below for synonymy)BR65
`--+--+--DialypetalumCM16
| |--+--L. gloria-montisCM16
| | `--L. villosaCM16
| `--TrematolobeliaCM16
| |--T. kauaiensisCM16
| `--T. macrostachysCM16
`--+--+--+--L. boninensisCM16
| | `--+--L. niihauensisCM16
| | `--+--L. hypoleucaCM16
| | `--L. yuccoidesCM16
| `--+--+--L. longisepalaCM16
| | `--L. morogoroensisCM16
| `--+--L. stricklandiaeCM16
| `--+--L. exaltataCM16
| `--L. fistulosaCM16
`--+--+--L. gregorianaCM16
| | |--L. g. ssp. gregorianaCM16
| | `--L. g. ssp. sattimaeCM16
| `--+--+--L. columnarisCM16
| | `--L. gibberoaCM16
| `--+--Sclerotheca DC. 1839CM16, KC01
| | `--S. jayorumCM16
| `--+--L. thulinianaCM16
| `--Apetahia longistigmataCM16
`--+--+--CyaneaCM16
| `--+--L. leschenaultianaCM16
| `--+--L. nicotianifoliaCM16
| `--L. seguiniiCM16
`--+--BrighamiaCM16
| |--B. insignisCM16
| `--B. rockiiCM16
`--DelisseaCM16
|--D. rhytidospermaCM16
|--D. subcordataCM16
`--D. undulataCM16
Lobelia incertae sedis:
L. aberdaricaCM16
L. aguanaCM16
L. arenariaCM16
L. assurgensJS87
|--L. a. var. assurgensJ87
`--L. a. var. santa-claraeJ87
L. calcarataCM16
L. christiiJS87
L. deckeniiCM16
L. dentataH87
L. dioicaLK14
L. douglasianaLK14
L. dunniiH93
|--L. d. var. dunniiH93
`--L. d. var. serrataH93
L. erectiusculaO88
L. fenestralisCM16
L. flexuosaCM16
L. fulgensD59
L. giberroaE09
L. gracilisH87
L. hereroensisCV06
L. hotteana Judd & Skean 1987JS87
L. karissimbensisPB27
L. kauaensisCM16
L. leucotosLK14
L. mcvaughiiCM16
L. nanaCM16
L. perpusilla Hooker 1853CM16, A61 [=Pratia perpusilla Hooker 1864A61]
L. rarifoliaOS04
L. rhynchopetalumCM16
L. robustaJS87
L. rotundifoliaJS87
L. stenophyllaBR65
L. stuhlmanniPB27
L. tenuiorGK00
L. vivaldiiCM16
L. wollastoniiPB27
L. sect. HemipogonBR65
|--L. alata Labillardière 1804BR65
`--L. pratioides Bentham 1869BR65
L. sect. HolopogonBR65
|--L. gibbosa Labillardière 1804 [incl. L. browniana, L. microsperma, L. simplicicaulis]BR65
`--L. rhombifolia De Vriese 1845BR65
Isotoma fluviatilis Mueller 1869CM16, BR65 [=Lobelia fluviatilis Brown 1810BR65, Laurentia fluviatilis (Brown) Wimmer 1948BR65; incl. Lo. inundata Brown 1910BR65]
Isotoma petraea Mueller 1852 [=Laurentia petraea (Mueller) Wimmer 1948]BR65
Isotoma scapigera Don 1834 [=Lobelia scapigera Brown 1810, Laurentia scapigera (Brown) Endlicher 1838]BR65
Lobelia angulata Forster 1786CM16, A61 [=Pratia angulata (Forster) Hooker 1844A61; incl. L. littoralis Cunningham 1839A61, P. angulata var. minor Carse 1930A61, P. angulata var. obovata Wimmer 1943A61, Lobelia rugulosa Graham 1829A61, P. treadmanii msA61]
Lobelia linnaeoides (Hooker) Petrie 1891 [=Pratia linnaeoides Hooker 1864; incl. L. linnaeoides var. brevipilis Wimmer 1953]A61
Lobelia physaloides Cunn. 1839CM16, A61 [=*Colensoa physaloides (Cunn.) Hooker 1853A61, Pratia physaloides (Cunn.) Hemsl. 1886A61]
Lobelia roughii Hooker 1864CM16, A61 [incl. L. roughii var. alces Wimm. 1953A61]
*Type species of generic name indicated
References
[A61] Allan, H. H. 1961. Flora of New Zealand vol. 1. Indigenous Tracheophyta: Psilopsida, Lycopsida, Filicopsida, Gymnospermae, Dicotyledones. R. E. Owen, Government Printer: Wellington (New Zealand).
[BR65] Black, J. M., & E. L. Robertson. 1965. Flora of South Australia. Part IV. Oleaceae–Compositae. W. L. Hawes, Government Printer: Adelaide.
[B06] Burgoyne, P. M. 2006. Review: Plants of the Simen. A flora of the Simen Mountains and surroundings, northern Ethiopia. Bothalia 36 (2): 253.
[CV06] Craven, P., & P. Vorster. 2006. Patterns of plant diversity and endemism in Namibia. Bothalia 36 (2): 175–189.
[CM16] Crowl, A. A., N. W. Miles, C. J. Visger, K. Hansen, T. Ayers, R. Haberle & N. Cellinese. 2016. A global perspective on Campanulaceae: biogeographic, genomic, and floral evolution. American Journal of Botany 103 (2): 233–245.
[D59] Darwin, C. 1859. The Origin of Species by Means of Natural Selection, or the preservation of favoured races in the struggle for life 1st ed. John Murray: London.
[E09] Ensermu K. 2009. Three new species of Acanthaceae from Ethiopia. Kew Bulletin 64 (1): 57–65.
[GK00] Gibson, N., & G. J. Keighery. 2000. Flora and vegetation of the Byenup-Muir reserve system, south-west Western Australia. CALMScience 3 (3): 323–402.
[H87] Haviland, E. 1887. Flowering seasons of Australian plants. No. II. Proceedings of the Linnean Society of New South Wales, series 2, 1 (4): 1103–1104.
[H93] Hickman, J. C. (ed.) 1993. The Jepson Manual: Higher Plants of California. University of California Press: Berkeley (California).
[J87] Judd, W. S. 1987. Floristic study of Morne La Visite and Pic Macaya National Parks, Haiti. Bulletin of the Florida State Museum—Biological Sciences 32 (1): 1–136.
[JS87] Judd, W. S., & J. D. Skean Jr. 1987. Three new angiosperms from Parc National Pic Macaya, Massif de la Hotte, Haiti. Bulletin of the Florida State Museum—Biological Sciences 32 (1): 137–150.
[KC01] Kirk, P. M., P. F. Cannon, J. C. David & J. A. Stalpers. 2001. Ainsworth & Bisby’s Dictionary of the Fungi 9th ed. CAB International: Wallingford (UK).
[LK14] Lyons, M. N., G. J. Keighery, L. A. Gibson & T. Handasyde. 2014. Flora and vegetation communities of selected islands off the Kimberley coast of Western Australia. Records of the Western Australian Museum Supplement 81: 205–244.
[OS04] Obbens, F. J., & L. W. Sage. 2004. Vegetation and flora of a diverse upland remnant of the Western Australian wheatbelt (Nature Reserve A21064). Journal of the Royal Society of Western Australia 87 (1): 19–28.
[O88] Ohba, H. 1988. The alpine flora of the Nepal Himalayas: an introductory note. In: Ohba, H., & S. B. Malla (eds) The Himalayan Plants vol. 1. The University Museum, University of Tokyo, Bulletin 31: 19–46.
[PB27] Pilsbry, H. A., & J. Bequaert. 1927. The aquatic mollusks of the Belgian Congo, with a geographical and ecological account of Congo malacology. Bulletin of the American Museum of Natural History 53 (2): 69–602, pls 10–77.
[P88] Polunin, I. 1988. Plants and Flowers of Malaysia. Times Editions: Singapore.