Cultivating Palmaria palmata - Bord Iascaigh Mhara

Chapter 2 - Biology of Palmaria palmata
2.1 Taxonomic classification
Phylum Rhodophyta
Sub-phylum Eurhodophytina
Class Florideophyceae
Sub-class Nemaliophycidae
Order Palmariales
Family Palmariaceae
Species Palmaria palmata (Linnaeus) O.
Description of Palmaria palmata
Kuntze (1891)
The red alga Palmaria palmata has a flat thallus which is
typically divided in a fork-like manner (dichotomously) or
grows palmately, i.e. into lobes radiating from the centre
of the fronds. The texture of fronds is membranous or
leathery. The fronds arise from a small discoid holdfast
either attached singly or clustered together in groups on
the substrate. Stipes are indistinct and often less than 5
mm in length. Mature fronds commonly grow to about 50
cm but can reach a length of up to one metre. Older
plants often show marginal outgrowths of new fronds
from the primary blade. The morphology can be very
variable depending on the environmental conditions
(Fig. 2.1). Finely dissected forms of Palmaria, known as
P. palmata var. sarniensis and var. sobolifera, can be
found as well as the typical form (var. palmata). These
two ecotypes tend to occur in more sheltered and silty
sites than var. palmata. Palmaria palmata is a perennial
species showing new growth of fronds every year. The
maximal lifespan of fronds is not known.
Fig. 2.1. Palmaria palmata. A (middle): Habit of typical
tetrasporophyte plant. B (right): Cross section through
thallus of tetrasporangial plant. C (left): Morphology of
ecotype Palmaria palmata var. sarniensis (from Irvine,
1983).
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