Lomentaria benahoarensis (Lomentariaceae, Rhodophyta), a diminutive epiphytic new species from La Palma, Canary Islands (eastern Atlantic Ocean)
Date
2009Abstract
The marine red alga Lomentaria benahoarensis sp. nov.
from the Canary Islands is described. Plants grow epiphytically on Corallina elongata forming turfs of creeping
axes attached by lateral discoid holdfasts and erect axes
up to 12 mm high. Erect axes are terete to slightly compressed, 200–300(–1000) mm broad, radially branched
up to three orders, with laterals progressively thinner,
constricted only at the bases of terminal axes. The cortex
is three-layered with the outermost cortical cells arranged
in a near-continuous surface layer. Medullary filaments
form a loose network of narrow elongate cells, which
bear secretory cells. Gametophytes are dioecious with
spermatangia formed in continuous spermatangial sori;
cystocarps are urceolate and ostiolate. Tetrasporangia
are subspherical and formed in depressed rounded sori
in slightly swollen regions in the middle of fertile terminal
axes. The new species has no single unique feature, but
differs from the other Lomentaria species by a distinctive
combination of attributes. Closest related species to
Lomentaria benahoarensis appear to be L. corallicola,
L. gracillima, L. monochlamydea, L. orcadensis, L. rawitscheri, and L. tenerrima. Although all these species have
a diminutive, decumbent habit and lack regular constrictions in axes, the number of cortical cell layers and the
arrangement of outer cortical cells distinguish them.