M. Masuda et K. Kogame, A TAXONOMIC STUDY OF THE GENUS LAURENCIA-(CERAMIALES, RHODOPHYTA) FROM VIETNAM - V - LAURENCIA CONCRETA CRIBB AND LAURENCIA-DINHII SP. NOV, Cryptogamie. Algologie, 19(3), 1998, pp. 201-212
The red alga Laurencia concreta Cribb (Rhodomelaceae, Ceramiales), rep
orted for the first time from Vietnam, is characterised by the product
ion of two vegetative periaxial cells from each axial segment. This, i
n combination with other features, confirms its inclusion in the subge
nus Chondrophycus. Laurencia dinhii Masuda et Kogame, sp. nov., endemi
c to southern Vietnam, is characterised by the following set of morpho
logical features: 1) a basal system composed of a single disc from whi
ch a few terete to subterete axes arise; 2) the production of two vege
tative periaxial cells from each axial segment; 3) the presence of a p
alisade-like superficial cortical layer, 3) the absence of projecting
superficial cortical cells; 5) the absence of longitudinally oriented
secondary pit-connections between contiguous superficial cortical cell
s; 6) the absence of lenticular thickenings in the walls of medullary
cells; 7) the presence of intercellular spaces between contiguous medu
llary cells; 8) a perpendicular arrangement of tetrasporangia, each of
which is produced from the second periaxial cell in each fertile segm
ent; 9) procarps produced from the last-formed (fourth) periaxial cell
of the terminal segment of a two-celled female trichoblast; and 10) f
lask-shaped cystocarps.