Conservation status of New Zealand indigenous vascular plants, 2012
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2012 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2009 and replaces all previous NZTCS lists for vascular plants. Authors: Peter J. de Lange, Jeremy R. Rolfe, Paul D. Champion, Shannel P. Courtney, Peter B. Heenan, John W. Barkla, Ewen K. Cameron, David A. Norton and Rodney A. Hitchmough. File size: 792KB
Taxonomic Notes
Pseudognaphalium Krip. is a genus that needs critical evaluation as there is some suggestion that it might be better placed in Helichrysum Mill., whilst many botanists favour recognition of Laphangium Tzvelev for at least some of those plants referred to Pseudognaphalium (e.g., Greuter 2003). These generic issues aside, at the species level the New Zealand plants referred to the Northern Hemisphere P. luteoalbum (L.) Hilliard et B.L.Burtt remain problematic. New Zealand plants do not look like the type of that species and there is range of variation evident. There have been attempts to segregate that variation into informal tag name 'units', such as P. "coast", P. "Kaitorete", P. "mountain", and P. "Zoo". However, some of the characters used to recognise these units have proved unstable in cultivation. Further critical study is needed not only to examine the variation present in New Zealand but also the status of Gnaphalium luteoalbum var. incanum A.Rich.—proposed for New Zealand plants by Richard (1832), and accepted by Allan (1961) but dismissed by Webb et al. (1988) as part of the variation within their broad worldwide concept of P. luteoalbum. Notably neither Allan (1961) or Webb et al. (1988) elaborated on their decisions with any critical taxonomic evidence; Allan (1961) says nothing whilst Webb et al. (1988) offered an opinion. Any taxonomic study of New Zealand plants would also need to consider those Australian and Pacific plants currently referred to Pseudognaphalium luteoalbum.
Pseudognaphalium ephemerum de Lange was proposed as a new name (nomen novum) for Gnaphalium luteoalbum var. compactum Kirk (de Lange et al. 2010). That species has not been widely accepted either and requires further critical study. The problem being that the assumption by field botanists that any small, flat Pseudognaphalium growing in Eastern South Island ephemeral wetlands (on lake margins and tarns growing on mud left as waters recede during summer) is this species, is not always valid as other races of Pseudognaphalium can adopt that morphology and will grow in these habitats as well—their recognition requires cultivation. In this regard P. ephemerum s.s is best recognised as being a small plant with strict annual habits that is very difficult (if not impossible) to cultivate. Whatever its status, for now many field botanists and ecologists accept it as a valid species.
Therefore, pending further taxonomic investigation and with the exception of Pseudognaphalium ephemerum, a broad concept of P. luteoalbum is used here.
References and further reading
de Lange, P.J.; Heenan, P.B.; Norton, D.A.; Rolfe, J.R.; Sawyer, J. 2010: Threatened plants of New Zealand.Christchurch, Canterbury University Press. 450 p
Greuter, W. 2003: The Euro+Med treatment of Gnaphalieae and Inuleae (Compositae) - generic concepts and required new names. Willdenowia 33: 239-244
Kirpicznikov, M. E.; Kuprijanova, L. A. 1950: Morphological-geographical and palynological contributions to the understanding of the genera of the subtribe Gnaphaliinae. Trudy Botanicheskogo Instituta Akademii Nauk SSSR. Series 1. Flora i Sistematika Vyssikh Rastenii. Acta Instituti Botanici Academiae Scientiarum URPSS series 1(9): 7-37.
Richard, A. 1832: Essai d'une Flore de la Nouvelle Zélande. In: Botanique. Essai d'une Flore de la Nouvelle Zélande[1]-376
Tzvelev, N. N. 1993: Notes on some Caucasian Asteraceae and Araceae. Byulleten' Moskovskogo Obshchestva Ispytatelei Prirody, Otdel Biologicheskii 98(6): 99-108
Webb, C.J.; Sykes, W.R.; Garnock-Jones, P.J. 1988: Flora of New Zealand. Vol. IV. Naturalised Pteridophytes, Gymnosperms, Dicotyledons. Christchurch, Botany Division DSIR