Like the Norweigian Blue Pratia Has Ceased To Be
The generic distinction of Hypsela, Isotoma and Pratia from Lobelia has always been problematic, and for most of the New Zealand species recognised in these genera combinations have long existed in Lobelia as well. In two comprehensive papers published in the March issue of the New Zealand Journal of Botany Vol. 46, Heenan et al. (2008) and Knox et al. (2008) completely place these satellite genera back into Lobelia. In the process four new species Lobelia carens, L. fatiscens, L. fugax and L. glaberrima are described – all threatened to some extent. Previously Lobelia carens was included within Hypsela rivalis, while L. fatiscens had been incorrectly regarded as the same as Isotoma fluviatilis (R.Br.) F.Muell. ex Benth., which as any horticulturist would know is an Australian species that never was in New Zealand. Because the epithet “rivalis” is preoccupied in Lobelia, a new species name – Lobelia ionantha - for the South Island plant long known as Hypsela rivalis is provided.Both papers are based on careful consideration of morphological and cytological evidence backed up by detailed phylogenetic reconstructions based on DNA sequence data. The only New Zealand Lobelioid to remain unmolested – at least for the time being – is Colensoa, an oddity that was never satisfactorily placed in Lobelia or Pratia, and so had been reinstated by de Lange & Cameron (1999). Current views are that Colensoa is a “sound” genus but that some northern Australian taxa currently assigned to other genera may in time be placed there, as might some Malesian species which need further critical study. As for the traditionally accepted New Zealand lobelia, further study into the relationship of Lobelia anceps to L. alata is also needed.
The names now available for the New Zealand lobelioids are:
Colensoa physaloides (A.Cunn.) Hook.f.
Lobelia arenaria (Hook.f.) Heenan et de Lange
Lobelia anceps L.f.
Lobelia angulata G.Forst.
Lobelia carens Heenan
Lobelia fatiscens Heenan
Lobelia fugax Heenan, S.P.Courtney et P.N.Johnson
Lobelia glaberrima Heenan
Lobelia ionantha Heenan
Lobelia linnaeoides (Hook.f.) Petrie
Lobelia macrodon (Hook.f.) Lammers
Lobelia perpusilla Hook.f.
Lobelia roughii Hook.f.
References:
de Lange, P.J.; Cameron, E.K. 1999: The Vascular Flora of Aorangi Island, Poor Knights
Islands, Northern New Zealand. New Zealand Journal of Botany 37: 433-468.
Heenan et al. 2008: Generic placement in Lobelia and revised taxonomy for New Zealand species previously in Hypsela and Isotoma (Lobeliaceae). New Zealand Journal of Botany 46: 87–100
Knox et al. 2008: Phylogenetic position and relationships of Lobelia glaberrima (Lobeliaceae), a new alpine species from southern South Island (New Zealand). New Zealand Journal of Botany 46: 77–85
Posted: 31/03/2008