• ALGAE
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• v.18 no.2
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• pp.107-119
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• 2003

Neosiphonia is separated from the traditionally well known genus Polysiphonia (Rhodomelaceae, Rhodophyta) and 12 species includes in Korea. In this study, the vegetative and reproductive developments of two Neosiphonia species, N. decumbens (Segi) M.S. Kim et I.K. Lee and N. harlandii (Harvey) M.S. Kim et I.K. Lee, are reinvestigated. N. decumbens is diagnosed by following combination of the characters: plants 1-3 cm high, dwarf, decumbent, main axes indistinct, irregularly branched in dichotomous manner, and alternately or secundly ramified with wide angles above. N. harlandii is distinguished by the features: plants 4-8 cm high, usually solitary and saxicolous, erect, densely corticated at base of distinct main axes, rather irregularly alternate in branch, and with cicatrigenous branchlets developed numerously on every part of frond. The two species share typical characteristics of the genus Neosiphonia, such as a base attached by unicellular rhizoids, cut off by cross wall, pericentral cells in 4, trichoblasts moderately developed near the apex of branches, leaving persistent scar-cells, tetrasporangia arranged in a spiral series, procarps with 3-celled carpogonial branch, and spermatangial branches arising as a primary branch of trichoblast. Taxonomy of the two Neosiphonia in regard to Polysiphonia is discussed.

• ALGAE
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• v.21 no.3
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• pp.287-294
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• 2006

Neosiphonia japonica is a rhodomelacean red alga that occurs in Korea, Japan, China, far-east Russia, northwest America, and New Zealand. Although it is distinguished by a bush-like habit having four pericental cells with cortication and numerous branches on axes, the taxonomy of N. japonica is still problematic. To investigate the taxonomy and phylogeny of the species, we analyzed rbcL and phycoerythrin (cpeA/B) genes from 19 samples of N. japonica and putative relatives. Phylogenetic trees from both genes show that N. japonica from Korea, Japan, New Zealand, and USA is clearly separated from N. decumbens, N. harlandii, and N. flavimarina from the Pacific Ocean. Instead, N. harveyi from the Atlantic Ocean was more related to N. flavimarina than to N. japonica. This result supports morphological and distributional differences between N. japonica and N. harveyi. However, the close relationship between these species suggests that they might have a recent most common ancestor. This is the second report to use the cpeA/B gene for evaluating species diversity in the Rhodophytes.