Lepidothamnus laxifolius

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Lepidothamnus laxifolius
Conservation status
Scientific classification
Kingdom: Plantae
Division: Pinophyta
Class: Pinopsida
Order: Pinales
Family: Podocarpaceae
Genus: Lepidothamnus
Species: L. laxifolius
Binomial name
Lepidothamnus laxifolius
Hook.f. Quinn.

Lepidothamnus laxifolius, commonly known as the Pygmy pine or Mountain rimu, is a species of conifer in the Podocarpaceae family. It is endemic to New Zealand, where it is found on North Island, South Island and Stewart Island.

Distribution[edit]

Lepidothamnus laxifolius is a high alpine specialist found in high-altitude bog communities and in scrub, often in association with Halocarpus bidwillii and Podocarpus nivalis. Example locations include Tongariro National Park and Arthur's Pass. On Stewart Island it is found in lowland as well as in montane areas.

Description[edit]

It has a scrambling prostrate habit and plants as little as 8 cm in height have been observed in fruit. Branches may be up to 5 mm in diameter and up to 1 metre long. Its cones are red and fleshy, and borne terminally on the horizontal branches.[1] It is believed to be the smallest conifer in the world and is rarely bigger than a small low-growing shrub.[2]

Taxonomy[edit]

The genus Lepidothamnus was once part of Dacrydium in the classification by Bentham and Hooker in 1880. However, current taxonomy separates it as a distinct genus with three species, one endemic to southern Chile and the other two in New Zealand. All three species have a distinctive cone morphology not shared with other podocarps with its erect ovule, as well as the absence of resin ducts in the leaves. These three species also synthesise cupressuflavone as their major biflavenoid – a feature not found in other podocarps.[3] They have narrow, linear spreading juvenile leaves that gradually change into more strongly keeled and appressed scales. Female cones are borne singly and at the ends of branches and each has 3–5 bracts with very elongated bases. Each fertile bracts supports an erect ovule in its axil and this ovule remains erect throughout its development.

References[edit]

  1. ^ Dallimore, William, Albert Bruce Jackson, and S.G. Harrison. 1967. A Handbook of Coniferae and Ginkgoaceae, 4th ed. New York: St. Martin's Press. xix, 729 p.
  2. ^ Dobson Nature Walk: the Natural History of an Alpine Pass, New Zealand Department of Conservation, 2006, ISBN 0-478-14068-1
  3. ^ Quinn, C.J. 1982. Taxonomy of Dacrydium Sol. ex Lamb. emend. de Laub. (Podocarpaceae). Australian Journal of Botany 30: 311–320.