Pteris hivaoaensis
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Illustration of Pteris hivaoaensis |
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| Lorence & KRWood |
Pteris hivaoaensis is a plant from the genus of pteris within the family of pteridaceae (Pteridaceae). It is only known from the type location on the island of Hiva Oa , which is one of the Marquesas Islands in the South Pacific .
description
Pteris hivaoaensis is a perennial herbaceous plant . It grows as a lithophytic fern . It forms an upright, 3 to 7 centimeter long rhizome , which is covered with scales and has a diameter of 1.5 to 2.5 centimeters. Often several rhizomes grow next to each other. The golden brown hair-like scales on the rhizome are needle-shaped with a length of 0.1 to 0.2 centimeters.
Each rhizome has upright or arched fronds arranged like tufts, which are up to 30 centimeters long with the stem. The dark hazel-brown frond stems are about half as long as the fronds and around 0.1 centimeters thick. The frond stalks are furrowed on the top and covered with a few light brown, sickle-like scales at the base, which are linear to linear-lanceolate with a length of 2 to 3 millimeters and a width of 0.1 to 0.5 millimeters. The scales have entire margins. The stems are also sparsely covered with wart-like glands.
The two- to three-pinnate fronds are approximately 10 to 16 centimeters long and 5 to 9 centimeters wide and approximately ovoid to lanceolate and contain almost oppositely arranged pinnate leaves. The parchment-like, not articulated leaflets are usually simply pinnate even over a large part of their length and sit on the frond stalk or stand on a stalk up to 2 millimeters long. The upper leaflets have two to three pairs of sickle-shaped lobes, the size of which depends on the size of the leaflet, with the largest lobes being found on the lowest and therefore largest leaflets. The pinnate lobes are 0.3 to 2.5 millimeters long and 0.3 to 11 millimeters wide, linear-oblong to linear-triangular. The edges of the lobes are notched or serrated and the tips of the lobes are rounded or tapered. The lowest leaflets are lanceolate, slightly receded and have six to seven pairs of sickle-shaped lobes. These pinnate lobes are between 5 and 8 millimeters wide, with the widest point slightly above the base of the lobe and they have entire margins which are also notched or toothed towards the tapering tip of the lobe. The single sickle-shaped to almost linear end lobe of the leaflets has notched lobes. Sterile leaflets have finely serrated margins, with each end of the leaf veins having a tooth, and the frond-stem-like central veins are furrowed on the top while rounded on the underside.
The sori are absent at the tips of the leaflets and are covered by a light brown indusium with entire margins. The spores are colored light brown.
Occurrence
Pteris hivaoaensis is endemic to the island of Hiva Oa , one of the Marquesas islands in the southern Pacific . Pteris hivaoaensis has so far only been found on a rock wall along a river at an altitude of about 930 meters. This damp rock face lies in the shadow of a damp forest in which Cheirodendron bastardianum , Crossostylis biflora , Metrosideros collina and Weinmannia marquesana grow. Alsophila tahitensis , Cyrtandra species, Freycinetia species, Leptochloa marquisensis , Melicope species, shrub species ( Psychotria spec.) And numerous other vascular spore plants also grow as socialized species .
Systematics
The first description of Pteris hivaoaensis was made in 2011 by David H. Lorence and Kenneth Richard Wood in phytokeys , number 4, page 28. The specific epithet hivaoaensis refers to the island of Hiva Oa , on which this species is endemic.
swell
- David H. Lorence, Warren L. Wagner, Kenneth R. Wood, Alan R. Smith: New pteridophyte species and combinations from the Marquesas Islands, French Polynesia . In: PhytoKeys . No. 4 , 2011, ISSN 1314-2003 , p. 5-51 , doi : 10.3897 / phytokeys.4.1602 .
Individual evidence
- ↑ a b c d e f David H. Lorence, Warren L. Wagner, Kenneth R. Wood, Alan R. Smith: New pteridophyte species and combinations from the Marquesas Islands, French Polynesia . In: PhytoKeys . No. 4 , 2011, ISSN 1314-2003 , p. 5-51 , doi : 10.3897 / phytokeys.4.1602 .
- ↑ Pteris hivaoaensis. In: The International Plant Names Index. www.ipni.org, accessed November 7, 2015 (English).
