Chapter 1: The Characeae Plant

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1.2.3 The Lamprothamnium succinctum group of species
The original collection of Lamprothamnium succinctum was made in Libya, North Africa,
and was described as a species of Chara (A. Braun in Ascherson 1876). It was recognised as
a species of Lamprothamnium by Wood (1962). The species was confusing because of the
poor expression of the vegetative characters that characterise the genus i.e. downward
pointing stipulodes and verticillate bract cells, and the presence of reproductive organs at the
base of the whorl which indicated a relationship with Chara corallina and C. australis (Braun
and Nordstedt 1882). Wood (1965) amalgamated specimens from Mauritius and New
Caledonia with the Libyan specimens, because those specimens also had reduced stipulodes
and bract cells, and gametangia at the base of the whorl. Later he placed similarly
depauperate species of Lamprothamnium in Australia in L. papuluosum, describing a new
form, f. succintoideum (Wood 1972) for them (Fig. 1.8). However, despite records of the
species in Australia (García et al. 2002) there is no evidence that L. succinctum occurs over
such a wide area, from Northern Africa to islands in the Indian and the Pacific Oceans, and in
southern Australia. It is more likely that there are additional species with similar
characteristics. The illustrations provided of the Mauritian species in Imahori and Wood
(1965) display a different arrangement of reproductive organs from the type material, so that
specimen, at least, is unlikely to be conspecific with L. succinctum. In the absence of an
updated taxonomy specimens of L. succinctum that have been collected from places other
than the Libyan desert (Braun and Nordstedt 1882) and used in physiological studies, can be
called L. sp aff. succinctum. Australian specimens in this group are generally long and
slender, with few or short stipulodes below the branchlet whorls (Fig. 1.8a), and few or short
bract cells (Fig. 1.8b). The fertile whorls can be contracted into the typical ‘fox-tails’ of the
genus, but the antheridia occur on short stalks outside the base of the whorls, and on the
branchlets (Fig. 1.8c, d), and the oogonia are clustered within the whorl of branchlets as well
as on the branchlets (Fig. 1.8c, e). This taxon is particularly useful in physiological studies
because of its elongated internodes.
1.2.4 Lamprothamnium inflatum
The ‘inflated’ charophyte Lamprothamnium inflatum (Fil. & G. O. Allen ex Fil) A. García &
K.G. Karol has had a long and confused taxonomic history, largely because of its unusual
morphology (Fig. 1.9). When growing in the field the young thallus appears as a (dense or
sparse) mat of green bubbles erupting from the surface of the mud, the bubbles being the
swollen tips of the branchlets. As plants mature the narrow axis elongates and dense whorls