Thamnophyllis lacerata Womersley & R.E.Norris
Australian Journal of Botany. Supplementary Series 25-27; figs 48-52, 94-96 (1971)
Conservation Code:
Not threatened
Naturalised Status: Native to Western Australia
Name Status:
Current
Scientific Description
John Huisman & Cheryl Parker,
Monday 20 June 2011
Habit and structure. Thallus red-brown to dark red, foliose, 5–15(–20) cm high and 10–25 cm across, usually deeply divided into several irregular parts or lobes 1–5 cm broad, with a smooth to irregularly undulate or ruffled margin, arising from a very short stipe; thallus robust and fairly tough, usually adhering well to paper on drying. Holdfast discoid, 1–3 mm across; epilithic or on shells. Structure. Thallus mostly 200–500 µm thick, consisting of 2–3 layers of small cortical cells grading to a central medulla of irregularly arranged large ovoid cells accompanied by relatively coarse filaments and very prominent darkly staining refractive ganglioid cells; medullary filaments formed from large medullary cells, 5–12(–15) µm thick, of ovoid to elongate cells, tending to be more densely grouped in the centre of the medulla in older parts of thallus; refractive cells formed in series from the growing apex, frequently connected, with or without a swollen central region and with 6–12 arms, each 8–20 µm thick, irregular in form, and often scarcely tapering along their length (though the arms often basally constricted); outer cortical cells in surface view ovoid to irregular, 3–5(–7) µm long, ovoid in sectional view of thallus.
Reproduction. Carpogonial branch systems monocarpogonial with an ovoid to clavate supporting cell bearing 10–14 elongate and often once-lobed subsidiary cells some of which may bear a second (and rarely a third) cell; only one carpogonial branch is formed. Fusion cell many-lobed, 120–200 µm across, forming several connecting filaments. Auxiliary cell systems 50–70 µm across, consisting of an ovoid auxiliary cell bearing 6–10 ovoid subsidiary cells, most of which usually cut off a second cell (and rarely a third); rarely a (probably) non-functional carpogonium may occur; connecting filament fusing with an auxiliary cell prior to gonimoblast development. Cystocarps 0.5–1 mm across, scattered, ostiolate, protruding somewhat on one side of the thallus, with spherical to ovoid carposporangia 10–15 µm across intermixed with gonimoblast filaments and medullary cells. Male thalli doubtfully observed; spermatangia apparently cut off from the outer cortical cells. Tetrasporangial thalli not observed.
Distribution. Head of the Great Australian Bight to Gulf St Vincent, S. Aust., and the east coast of Tas.
[After Womersley, Mar. Benthic Fl. Southern Australia IIIA: 247–249 (1994)]
