Laurencia catarinensis Cord.-Mar. & M.T.Fujii

Revta brasil. Boi 8-47-53 (/90S)

Laurencia catarinensis (Rhodomelaceae, Rhodophyta), a new species
from I lha de Santa Catarina, Brazil

MARILZA CORDEIRO-MARINO and MUTUE T. FUJII1

Segao de Ficología, Instituto de Botánica, Caixa Postal 4005, 01000 Sao Paulo, Brasil.

ABSTRACT - (Laurencia catarinensis (Rhodomelaceae, Rhodophyta), a new species from Ilha de Santa Catarina, Brazil).
Laurencia catarinensis sp. nov. (subgenus Laurencia section Laurencia) is described from Ilha de Santa Catarina, Brazil.
Morphological and cytological studies provide a detailed description for the new species. Differences and similarities with
Laurencia caraibica Silva (=Laurencia nana Howe), L. teñera Tseng, and L. articulata Tseng, all very close to the new
species are discussed. Pattern of branching, orientation of main axes, diameter of the branchlets, presence or absence of
coalesced axes, lenticular thickenings, and increase in size of medullar cells toward* the center of the thallus, were the
characteristics used for comparison. A haploid chromosome number of 28 was counted during diakinesis of the first
meiotic division.

RESUMO - (Laurencia catarinensis (Rhodomelaceae, Rhodophyta), nova espécie para Ilha de Santa Catarina, Brasil).
Laurencia catarinensis sp. nov. (subgénero Laurencia secgáo| Laurencia) é descrita para a Ilha de Santa Catarina, Brasil.
Estudos morfológicos e citológicos foram realizados visando fornecer uma descrigao detalhada para a nova espécie. Dife-
rengas e similaridades com Laurencia caraibica Silva (=Laurencia nana Howe), L. teñera Tseng e L. articulata Tseng sao
discutidas por tratarem-se de especies muito próximas á nova espécie. Padráo de ramificagao, orientado do eixo princi-
pal, diámetro dos rámulos, presenga e ausencia de ramos coalescentes, espessamentos lenticulares e aumento de tamanho
das células medulares em dire gao ao centro, foram as características usadas para comparagao. O número haplóide de ero- -
mossomas observado foi 28 e a sua contagem foi feita durante a diacinese.

Key words: Rhodomelaceae, Laurencia, new species, morphological and cytological data.

Introduction

During a survey of benthic marine algae of
Santa Catarina State, Brazil, a large quantity of
Laurencia was collected at Ilha de Santa Cata-
rina (27°36’S, 48°26’W). According to the lite-
rature this material was similar in habit and certain
anatomical characters to Laurencia caraibica Sil-
va (=Laurencia nana Howe), L. tenera Tseng and
L. articulata Tseng. Detailed morphological stu-
dies, however, revealed a set of characteristics not
shared by these three species or by any other spe-
cies of Laurencia. A new taxon is therefore propo-
sed. Cytological observations were carried out on
tetrasporangial plants. Mitosis was observed in
somatic trichoblast cells, and meiosis in tetraspo-
rangial mother-cells. The haploid chromosome
number is given.

Laurencia catarinensis Cordeiro-Marino & Fujii, sp.
nov. (Figure 1-13).

Plantaelparvae, virellae, carnosae, caespites densos
implicatosque formantes; axis principalis indeterminatus,
cylindricus, in partibus senioribus prostratus, junioribus

! Conselho Nacional de Desenvolvimento ( íentífico i
Tecnológico Research Fellow (Grant n° 10 3639
80-Z01

erectus, 900-1200/Llm diámetro; ramificatio plerumque
alternati-spiralis, interdum unilateralis, irregularis; rami
erecti cylindrici, altitudine 3.0-8.5mm; diámetro 750-
lOOOjLtm; ramuli ultimi breves, claviformes vel claviformi-
truncati, diámetro 78-108/Llm, dense aggregati; axis de-
cumbentes ad apices ramorum in hapteris divisi, substra-
tum contingentibus; anastomoses inter axis, ramos ramu-
losque carentes; cellulae epidemiales parum in superficie
thalli elevatae ad apices ramulorum; cellulae subcortica-
les medullosaeque thalli versus centrum gradatim cres-
centes; cellulae epidemiales, subcorticales medullosaeque
in sectione transversali parientibus tenuibus munitae;
cellulae medullosae lenticulariter haud pachydermae.

Plants small, greenish, entagled, cushion-like,
fleshy (Figure 1). Main axes with unlimited
growth, terete, decumbent in the oldest portion
and erect in the youngest, 900-1200jum diameter
(Figure 2). Branching mainly alternate spiral, so-
metimes unilateral to irregular. Branches erect,
terete, 3.0-8.5mm tall, 750-1000pim diameter;
branchlets short, club-shaped, with rounded oi
truncate apices, 78-108/nmdiameter, densely arran
ged. Axes decumbent with haptera emitting from
the apical portion of branches in contact with
the substrate; coalesced axes, branches or branch-
lets absent. Epidermal cells projecting slightly
near the apex; subcortical and medullary cells
gradually increasing in size towards the center
of the thallus; epidermal, subcortical and me-
dullary cells thin-walled in cross section: medul-
lary cells without lenticular thickenings.

NEW YORK BOTANICAL GARDEN

00900226

SP J 64 a S4

(Jio w )

OmUnd.. tóa/a e/o/r. //a/l )
4/ I- f9fi	- '

fo/de//c-A/au?!£-

«WYORiT

^SOTA-'-CAL
S' /

VO ^