Cyclosorus florencei
| Cyclosorus florencei | ||||||||||||
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The holotype of Cyclosorus florencei |
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| Scientific name | ||||||||||||
| Cyclosorus florencei | ||||||||||||
| ARSm. & Lorence |
Cyclosorus florencei is a species of the genus Cyclosorus withinthe marsh fern family (Pteridaceae). It is only known from the island of Hiva Oa , which is one of the Marquesas Islands in the southern Pacific .
description
Cyclosorus florencei is a perennial herbaceous plant . It grows as a terrestrial fern . It forms a creeping rhizome that is up to 1 centimeter thick.
On each rhizome the fronds stand together in loose groups. The hairless frond stalks are light to straw brown, are up to 70 centimeters long and reach a diameter of up to 0.9 centimeters in the upper part. The base of the stems is sparsely covered with brown, lanceolate-shaped scales. At the transition from the stem to the actual frond there are about ten pairs of greatly reduced leaflets, which are 0.1 to 1 centimeter long. The pairs of pinnate leaves are 2.5 to 4 centimeters apart.
The simply pinnate fronds reach a length of up to 60 centimeters without the receding uppermost leaflet, taper towards the pinnately split tip and contain up to 30 pairs of leathery leaflets. The largest of the leaflets are up to 12 centimeters long, between around 1.7 centimeters wide and have conically shaped and swollen aerophores at their base . These aerophores can be up to 0.5 millimeters in size. The base of the leaflets is not eyelet, while the tip is tailed to pointed. The leaflets are lobed on two-fifths to half of their entire width, with the three to four millimeter long lobes beveled to slightly sickle-shaped and have approximately pointed to rounded tips. The conspicuous leaf veins are clearly visible on the underside of the leaflets. Both the surface of the underside of the leaf and the veins can be almost hairless or covered with a few hairs less than 0.1 millimeters long. The leaf central nerve on the underside has light brown scales lying on it or slightly protruding, which are misshapen with a length of around 2 millimeters and a width of around 0.2 millimeters. Yellowish colored leaf glands are completely absent. The upper side of the leaf is hairless.
The Sori are in the middle of the leaf and have no indusium . The sporangia have yellowish, capsule-like glands that are around 0.1 millimeters in size.
Occurrence
Cyclosorus florencei is endemic to the island of Hiva Oa , which belongs to the Marquesas Islands in the southern Pacific . Cyclosorus florencei is only known from the type locality on the road between Atuona and Hanamenu . The species grows there in montane rainforests together with Crossostylis biflora , Freycinetia species, Metrosideros collina and Weinmannia marquesana .
Systematics
The first description of Cyclosorus florencei was made in 2011 by Alan Reid Smith and David H. Lorence and phytokeys . The specific epithet florencei honors Jacques Florence, who did a great job researching the flora of the Marquesas Islands and French Polynesia .
Cyclosorus florencei is possibly closely related to the species Cyclosorus glanduliferus , which occurs on Rarotonga , Samoa , the Solomon Islands and the New Hebrides, and to the species Cyclosorus stokesii native to Rapa Iti .
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 g 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 .
- ↑ Cyclosorus florencei. In: The International Plant Names Index. www.ipni.org, accessed on February 22, 2016 (English).
