Pteris hivaoaensis
| Notice: | This page is derived from the original publication listed below, whose author(s) should always be credited. Further contributors may edit and improve the content of this page and, consequently, need to be credited as well (see page history). Any assessment of factual correctness requires a careful review of the original article as well as of subsequent contributions.
If you are uncertain whether your planned contribution is correct or not, we suggest that you use the associated discussion page instead of editing the page directly. This page should be cited as follows (rationale):
Citation formats to copy and paste
BibTeX: @article{Lorence2011PhytoKeys4, RIS/ Endnote: TY - JOUR Wikipedia/ Citizendium: <ref name="Lorence2011PhytoKeys4">{{Citation See also the citation download page at the journal. |
Ordo: Pteridales
Familia: Pteridaceae
Genus: Pteris
Name
Pteris hivaoaensis Lorence & K. R. Wood sp. nov. – Wikispecies link – IPNI link – Pensoft Profile
Latin
Ab aliis Marquesas speciebus laminis 1-pinnatis usque ad 1-pinnato-pinnatifidis, apice cum 6-7 loborum paribus distalibus falcatis, glabris vel glabrescentibus stipitibus differt.
Type
Marquesas Islands: Hiva Oa: Temetiu, windswept ridges and drainages, 9°49'S, 139°4'W, 930 m (3050 ft), 24 August 1995, K. R. Wood 4374(Holotype PTBG-038496!; Isotypes BISH!, P!, PAP!, US!).
Description
Lithophytic ferns; rhizomes erect, clumping together, 3–7 cm long,15–22 mm in diameter, clothed in very narrow, golden-brown acicular hairlike scales 1–2 mm long. Fronds erect or arching-pendent, to 30 cm long, clustered at rhizome apex; stipes ca. ½ length of frond, up to 1 mm in diameter medially, atrocastaneous, grooved adaxially, sparsely pustulate-tuberculate, glabrous except for a few linear to linear-lanceolate, falcate scales 2–3 × 0.1–0.5 mm at bases, tan-brown, margins subentire; blades chartaceous, glabrous, narrowly ovate to lanceolate, 10–16 × 5–9 cm; proximal 2–3 pinnae consisting of subopposite, subequal pairs, 1-pinnate-pinnatifid for most of length, sessile or stalked up to 2 mm, non-articulate, bearing 2–3 pair of falcate lobes of increasing size proximally with maximum size at basiscopic lobe of lowest pinnae, lobes linear-oblong or linear-triangular 0.3–2.5 × 0.3–11 mm, apices rounded to acute, crenate to dentate, basal pinnae slightly reduced, blade distally pinnatifid, lanceolate, the apex pinnatifid, with 6–7 pairs of falcate lobes 5–8 mm wide above their bases, dilated basiscopically, margins mostly entire, tapering gradually to acute apices with crenate-dentate margins, single terminal lobe falcate or tapering to narrowly linear crenate margin; margins of sterile pinnae finely dentate with one tooth per vein ending; costae and costules grooved adaxially, rounded abaxially, similar to stipe in color; veins netted with 1–2 rows of areoles. Sori occasionally interrupted at sinuses and absent at apices of segment; indusia tan-brown with entire margins. Spores tan-brown.
Distribution
Known only from Hiva Oa, Marquesas Islands.
Ecology
This rare species is known only from the type location at 930 m on wet stream walls adjacent to wet forest dominated by Cheirodendron bastardianum, Crossostylis biflora, Metrosideros collina, Weinmannia marquesana var. marquesana and other associates including Alsophila tahitensis, Cyrtandra spp., Freycinetia sp., Leptochloa marquisensis (F. Br.) P. M. Peterson & Judz., Melicope spp., and Psychotria spp., interspersed with a rich pteridophyte understory. The main threats to this habitat are feral pigs and invasives plants including Elephantopus mollis Kunth, Psidium guajava, and Syzygium cumini (L.) Skeels.
Conservation status
Proposed IUCN Red List Category Critically Endangered (CR): B2a, B2b (i–iii), D); B2: total area of occupancy less than 10 km2 (ca. 5 km2). B2a, a single population known; b (i–iii), habitat continuing decline inferred; D, population estimated to number fewer than 250 mature individuals. The suitable habitat for Pteris hivaoaensis on Hiva Oa (ca. 315 km2) is indicated as an endangered environment, threatened by human activity (deforestation, fire), feral animals, and invasive plants, reducing the extent of the forest. D, the rarity of this species is supported by the lack of collections and the small extant area within a commonly collected island, i.e. with a single collection.
Etymology
This new species is named for its only known island of occurrence.
Discussion
Pteris hivaoaensis is quite distinct from the other Marquesan Pteris species, differing by its pinnate to pinnate-pinnatifid blades with glabrous or glabrescent stipes and the apex pinnatifid with 6–7 pairs of falcate lobes.
Original Description
- Lorence, D; Wagner, W; Wood, K; Smith, A; 2011: New pteridophyte species and combinations from the Marquesas Islands, French Polynesia PhytoKeys, 4: 5-51. doi
Images
|
