| Pteridophyte | Literature for Hymenasplenium unilaterale
Palmer, 2003. |
| Aspleniaceae -- The Spleenwort Family | Bibliography |
| Hymenasplenium unilaterale | |
Common name(s): spleenwort, pamoho |
| General Information | ||
|---|---|---|
| Distribution | Hawaii. Also widely distributed from China to Africa, Malaysia, southern Japan, Taiwan, China, and Polynesia.In the Hawaiian Islands, indigenous to Kaua`i, O`ahu, Moloka`i, Lana`i, Maui, Hawai`i. Does not occur in Hawaii according to Ke-Wang et al. 2018. New Phytologist, reassessment of the genus. Evidently Hymenasplenium excisum does occur in Hawaii; H. unilaterale s.l. appears to be a single variable species in Hawaii. It is a cryptic species complex (Xu et al., 2019), there is polyploidy in the genus, as well as apomixis across three evolutionary lines. Further study is needed to discern species names applicable to taxa in Hawaii which exhibit clinal variation in characters. (A. R. Smith, pers. comm. 2020).. |
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| Habitat | Locally common fern of wet, mossy forests, often near streams. | |
| Elevation | 200-1830 m |
|
| Habit |
Terrestrial or epipetric, small to medium-sized; rhizomes long-creeping, thin, up to 3.5 mm diameter. |
|
| Leaves |
Fronds erect, well separated, spaced up to 4 cm apart, 15-35 x 2- 4.5 cm, not proliferous; stipe and rachis thin, round to shallowly grooved, dark brown to black, shiny, glabrous; blade 1-pinnate, deltate-lanceolate, tips tapering gradually and evenly; pinnae 12-25 pairs, short-stalked, alternate, rectangular with somewhat tapering tips, strongly dimidiate with lower margins of pinnae nearly straight to moderately concave, usually less than 2.5 x 0.8 cm, costae close to lower margins, distal margins finely dentate; lower pinnae not or only slightly reduced; veins conspicuous, 1- to 2-forked. |
|
| Sori |
Sori to 3 mm long; indusia thin. |
|
| Notes |
Latin, unus, one, + lateralis, at the side, lateral to, alluding to the apparently one-sided dimidiate pinnae. |
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| Contributor |
Sally Eichhorn |