Species Description: Valves of this species are narrowly clavate and flat, very gradually widening from the somewhat capitate foot pole to the head pole, which is broadly rounded (Fig. 2, SEM). Cells are very narrowly wedge-shaped in girdle view (Fig. 1, colony form adapted from Haeckel 1904) with a very short septum. The head pole has a rimoportula subtending a series of short striae around the apex (Fig. 3, detail of Fig. 2). The foot pole normally lacks a rimoportula (Fig. 4, detail of Fig. 2) but the species is somewhat uncommon for Licmophora in that there are several rimoportulae scattered along the length of the valve (Fig. 5, valve center, SEM; and Fig. 3). The striae are transverse except at the poles, and consist of mostly subquadrate poroid areolae (Figs. 3-5). According to Sar & Ferrario (1990), the length is 135-260µm and the width is 4-7.5µm at the head pole and 3-4µm at the foot pole (Hustedt 1931-66, gives 60-300µm and 5-13µm). The striae number 29-34 in 10µm. This species is common in the IRL system, primarily attached to red or brown seaweeds.

Haeckel E. 1904. Kunstformen der Natur. Bibliographisches Instituts Verlag, Leipzig. 396pp.

Hustedt F. 1931-1966. Die Kieselalgen Deutschlands, Österreich und der Schweiz. In: Dr. L. Rabenhorst’s Kryptogamen-Flora von Deutschlands, Österreich und der Schweiz 7(1): 1-920; 7(2): 1-845; 7(3): 1-816. J Cramer Verlag, Weinheim.

Sar EA, Ferrario ME. 1990. Licmophora flabellata: Ultrastructure and taxonomy I. Implication. Diat Res 5: 403-408.

Annulus: A hyaline ring of slightly thickened silicon on a valve surface.

Areolae: A regularly repeated perforation through the cell wall.

Auxospore: A special cell that restores cell size; normally a result of sexual reproduction.

Auxospore Envelope: A hyaline envelope that surrounds the auxospore cell.

Auxosporulation: The process of auxospore formation.

Capitate: Head-shaped.

Fascia: A plain, unthickened transverse strip.

Foramina: Opening on one side of a complex areola.

Homothallic: Possessing both male and female capability in a single morphologically and physiologically identical cell.

Hyaline Line: An unperforated siliceous strip between two striae.

Interstriae: An unperforated siliceous strip between two striae.

Morphogenesis: A developmental sequence that causes an organism to develop its shape.

Mucilage: Glycoproteins and/or exopolysaccharides excreted by some diatoms.

Ocellus: A group of small pores surrounded by a thickened hyaline rim and raised from the surface of the valve.

Oogamous: Sexual reproduction in which the sperm is small and motile, and the egg is larger and nonmotile.

Oogonia: Female gametangia.

Otaria: Membranous costae that occur opposite each other on a valve, especially the genus Rhizosolenia.

Pili: Long siliceous hairs on a diatom valve.

Poroid: Simple unchambered hole through a diatom valve.

Pseudoseptum: A siliceous projection to the cell interior at the edge of the valve.

Rimoportula: A tubelike opening through the cell wall with an internal flattened tube or lip-like slit; also called labiate process.

Rimoportula Tube: The external portion of a rimoportula.

Rostrate: The blunt tapered end of a valve, shaped like a beak.

Spermatogonangia: In sexual reproduction, the cell that produces sperm cells.

Spinules: Little spines.

Uniseriate: Arranged in a single series of cells.

Vegetative Cells: Cells that are a result of asexual division.