Vegetation and flora of the Ben More — Chalk Range area of southern Marlborough South Island

Section: Habitat Classificationmentioning

confidence: 99%

“…Nomenclature Druce et al (1987) and Druce & Williams (1989) use lower-case letters as tag names for unnamed taxa, e.g., Melicytus sp. (a), Helichrysum intermedium var.…”

Section: Biogeographic Species Groupsmentioning

confidence: 99%

The nature of the lower North Island floristic gap

Rogers

1989

“…This survey was not extended to other parts of the South Island or the North Island. These grasses, however, were not reported in two recent accounts of extensive limestone habitats in western Nelson and southern Marlborough (Druce et al 1987;Druce & Williams 1989).…”

Section: G E O G R a P H I C Distributionmentioning

confidence: 91%

“…Like other indigenous plants confined to limestone, A. calcis is found mainly in sparse vegetation on skeletal rendzina-like soils (see also Druce et al 1987;Druce & Williams 1989). Available evidence indicates that these soils are alkaline, rich in CaCO3, high in available phosphorus, free-draining, and especially drought-prone in low-rainfall areas (New Zealand Soil Bureau 1968).…”

Section: Principal Ecological Featuresmentioning

confidence: 99%

Observations on the ecology and conservation ofAustralopyrum calcis(Triticeae: Gramineae) in New Zealand

Molloy¹

1994

The ecology and conservation of the newly described endemic calcicolous grass Australopyrum calcis are outlined. Of the two infraspecific taxa recognised, subsp, calcis is confined to Marlborough on Mesozoic limestone exposed for at least 2 million years, and subsp, optatum is restricted to Canterbury on Tertiary limestones exposed from about the mid Pleistocene.Limestone colluvium and karst landforms such as tor overhangs are the main contemporary habitats of these grasses, and both taxa grow on sparsely vegetated skeletal rendzinas that are strongly alkaline and high in CaCO3 and available phosphorus. Broadleaved low forest and "grey scrub" form the dominant natural vegetation of these habitats, and the indigenous flora comprises both wide-ranging species and regional or local endemics. Associated naturalised plants include many species recorded from limestones in Europe.The two subspecies tolerate moderate shade, avoid competition, and seem unpalatable to grazing animals. They appear to have retreated to suboptimal environments in small, relatively dry, high-risk refugia now surrounded by aggressive naturalised plants. Both taxa are therefore in danger of extinction, and although they are not constrained by their breeding system, their future in the wild will depend on soundly based practical conservation measures, especially the retention and enhancement of suitable habitats.The so-called calcicolous element of the New Zealand flora is considered to be underestimated in B93019 Received 2 February 1993; accepted 22 July 1993importance because of a rather narrow interpretation of the term. A broader definition is proposed that includes wild plants characteristic not only of limestones but also of other base-rich rocks, such as basalts, schists, and calcareous mudstones.The origin of Australopyrum and its migration to New Zealand are unknown and open to speculation. Available genetic and DNA information indicates a possible Asian origin, and current geological and fossil plant evidence suggests a mid-Tertiary entry to the country, perhaps during the Miocene or even earlier, and possibly involving one immigration event. Of the two taxa, subsp, optatum is considered the younger isolate. However, compared with other grasses such as Poa and Chionochloa, Australopyrum has not succeeded in diversifying in New Zealand environments and is a relict here, in contrast to its comparatively common relatives in Australia.The emergence of strips of Tertiary limestones by fault movements and the erosion of cover deposits is seen as a major factor in the evolution of calcicolous plants, including many new taxa observed during this study. Much of this speciation is regarded as recent, and has probably occurred since the early Pleistocene or even more recently.

“…astonii in the Waima Valley. The rock substrate for both subspecies is Amuri Limestone (Druce & Williams 1989), and the bluffs provide the same habitat in both places, and on the coastal hills at the Flaxbourne River mouth. Another unexpected result is the wide disjunction of 250 km in G. calcis subsp.…”

Section: Gentianella Serotinamentioning

confidence: 99%

A revision of the genusGentianellain New Zealand

Glenny

2004

Previous work on Gentianella and related genera is reviewed, particularly the taxonomic history of the New Zealand gentians and their generic placement. Phylogenetic analysis of DNA sequences shows the New Zealand gentians belong in Gentianella. The recently described Australasian genus Chionogentias is preceded by earlier names applied to South American species that belong in a Southern Hemisphere clade.Thirty species are recognised, including seven new species (G. angustifolia, G. calcis, G. decumbens, G. luteoalba, G. impressinervia, G. scopulorum, and G. stellata) and one species (G. magnifica) raised from varietal status. The identity of G. patula is clarified and the specific status of G. amabilis is affirmed. Thirteen subspecies are recognised, including a new subspecies within G. astonii (subsp. arduana) and four within a new calcicole species G. calcis (subspp. calcis, waipara, manahune, taiko). New subspecies are also made in G. corymbifera (subsp. gracilis), G. montana (subsp. ionostigma), and G. chathamica (subsp. nemorosa). G. montana var. stolonifera is the only existing variety this treatment continues to recognise. Four previously recognised species are reduced to synonymy (G. gracilifolia, G. matthewsii, G. tereticaulis, and G. townsonii). Descriptions and keys are provided for all species and subspecies recognised.Evidence is limited, but Gentianella appears to have arrived in New Zealand from South America either once or twice, and has probably dispersed once from New Zealand to Australia. Zealand appears to be in the southern half of the South Island. An initial radiation in the lower South Island was followed by northward range extensions and dispersal events. A second radiation occurred in the Nelson and Marlborough mountains.