(Patrick) Mayama in Mayama and Kawashima 1998 Category: Symmetrical biraphid
BASIONYM: Navicula mobiliensis var. minor Patrick 1959
Valves are linear-lanceolate, becoming slightly triundulate in larger specimens. Apices are cuneate. Striae are radiate, becoming more dense near the apices. The central area is transversely oriented, incomplete, asymmetric, and characterized by a distinct stigma. Few to many puncta are erratically scattered near the central area margin. The axial area is moderately narrow and lanceolate. Longitudinal lines are visible along the valve margin. The raphe is narrowly lateral, with hooked distal ends and proximal ends deflected to the opposite side. Areolae are coarse and easily visible in LM, measuring 18-20 in 10 µm.
Basionym: Navicula mobiliensis var. minor
Author: Patrick 1959
Length Range: 34-43 µm
Width Range: 10-12 µm
Striae in 10 µm: 16-24
Navicula mobiliensis var. minor var. nov.
Valva lineari ad linearem lanceolatam, apicub cuneatis. Area axiali distincta. Area centrali transversa. Stigma distincta in uno latere nodulis; compluribus punctis in altera latere areae centralis quae sunt separatae ab apicubus striarum. Striis radiatis per valvam. Longitudo, 34-43 μ (specimen typicum, 41 μ). Latitudo, 10-12 μ (specimen typicum, 11 μ). Striae, 16 in 10 μ in media valvae usque 24 in 10 μ apicibus valvae.
Valve linear to to linear-lanceolate, with wedge-shaped ends. Axial area distinct, central area transverse. On one side of the central nodule a distinct stigma; on the other side of the central area several puncta which are isolated from the ends of the striae. Striae radiate throughout the valve. Length, 34-43 μ (type, 41 μ). Breadth, 10-12 μ (type, 11 μ). Striae, 16 in 10 μ at center of valve to 24 in 10 μ at ends of valve.
The shape of the valve and the general characteristics of the axial and central areas are similar to that of the nominate variety. This variety differs in its smaller size, finer striae and the presence of several isolated puncta near the ends of the striae on the side of the central area opposite to the side bearing the stigma. Puncta usually 20-22 in 10 μ.
Specimen illustrated.–A-G.C. 44497 (holotype). Type locality.–Pennsylvania, Chester County, Ridley Creek near Garrett Mill Road, approximately one-fourth mile upstream from West Chester Pike, J. Wallace, November 1951. Distribution.–Only known from the type locality.
Johansen, J.R., Lowe, R., Gomez, S.R., Kociolek, J.P. and Makosky, S.A. (2004). New algal species records for the Great Smoky Mountains National Park, U.S.A., with an annotated checklist of all reported algal species for the park. Archiv für Hydrobiologie Supplement 150: 17-44.
Levkov, Z., Metzeltin, D. and Pavlov, A. (2013). Luticola and Luticopsis. In: Diatoms of Europe, Diatoms of the European Inland Waters and Comparable Habitats, Volume 7, Koeltz Scientific Books, pp. 698.
Mayama, S. and Kawashima, A. (1998). New combinations for some taxa of Navicula and Stauroneis, and avowed substitute for a taxon of Eunotia. Diatom 14: 69-71.
Patrick, R.M. (1959). New species and nomenclatural changes in the genus Navicula (Bacillariophyceae). Proceedings of the Academy of Natural Sciences of Philadelphia 111 (1959): 91-108 . http://www.jstor.org/stable/4064508
Patrick (1959) described this taxon from Pennsylvania. Although species in the genus Luticola are often found in soils and aerophilic habitats, we verified records in samples from rivers of Georgia and South Carolina. Along with Sellaphora japonica, L. minor is found both in rivers of the southeastern U.S. and in Japan - a curious disjunct distribution. L. minor has been reported from Japanese springs and rivers (Mayama and Kawashima, 1998).
Luticola minor is similar in shape to L. submobiliensis, but the valve length to width ratios of each taxon are distinct (below).
Comparison of length and width measures of L. minor (red circles) and L. submobiliensis (blue triangles).
Credit/Source: Meredith Tyree