(Frenguelli) Lange-Bertalot 2003 Category: Symmetrical biraphid
BASIONYM: Navicula pampeana Frenguelli 1926
REPORTED AS: Navicula cuspidata var. major (Patrick and Reimer 1966, p. 465, plate 44, fig. 1)
Contributor: Loren Bahls - June 2012
Length Range: 139-274 µm
Width Range: 29-45 µm
Striae in 10 µm: 10-12
Valves are very large and lanceolate with blunt, broadly rounded apices. The axial area is linear and barely wider than the raphe. The central area is slightly wider than the axial area and with straight or somewhat convex sides. The raphe is weakly lateral with moderately inflated proximal ends that bend slightly to one side. Distal raphe ends are hooked toward the same direction. Striae are parallel in the center, becoming weakly convergent and then weakly radiate near the apices. Areolae may be distinguished in LM and number 20-24 in 10 µm.
Meister (1912) described a taxon from Switzerland as Navicula cuspidata var. major, which Patrick & Reimer (1966) report from Ohio. It is not clear if these two taxa are conspecific.
Basionym: Navicula pampeana
Author: Frenguelli 1926
Length Range: 95-264 µm
Width Range: 23-45 µm
Striae in 10 µm: 10-12
Frenguelli, J. (1926). Contribuciones al Conocimiento de las Diatomeas Argentinas IV: Diatomeas fósiles del Prebelgranense de Miramar. Boletin Acad. Nacional Ciencias en Cordoba 29: 4-108.
Lange-Bertalot, H., Cavacini, P., Tagliaventi, N. and Alfinito, S. (2003). Diatoms of Sardinia: Rare and 76 new species in rock pools and other ephemeral waters. Iconographia Diatomologica 12, 438 pp.
Meister, F. (1912). Die Kieselalgen der Schweiz. Beiträge zur Kryptogamenflora der Schweiz, 4/1, 1–254.
Metzeltin, D., Lange-Bertalot, H. and García-Rodríguez, F. (2005). Diatoms of Uruguay. Compared with other taxa from South America and elsewhere. In: H. Lange-Bertalot (ed.), Iconographia Diatomologica. Annotated Diatom Micrographs. Vol. 15. Taxonomy-Biogeography-Diversity. A.R.G. Gantner Verlag K.G. 15:736 pp.
Patrick, R.M. and Reimer, C.W. (1966). The Diatoms of the United States exclusive of Alaska and Hawaii, V. 1. Monographs of the Academy of Natural Sciences of Philadelphia 13.
Craticula pampeana has been recorded from 7 prairie streams and wetlands in eastern Montana, where the water is alkaline and rich in sodium and sulfate with elevated dissolved solids (see table below). Here it is most frequently associated with Navicula rhynchotella, Nitzschia subvitrea, Planothidium engelbrechtii, Craticula buderi, Anomoeoneis costata, and Nitzschia commutatoides. This species was described from material collected in Argentina (Frenguelli 1926). It has also been reported (as Navicula cuspidata var. major) from Switzerland (Meister 1912) and Ohio (Patrick & Reimer 1966).
Poplar River, eastern Montana: home of Craticula pampeana.
Credit/Source: Loren Bahls
Abundance-weighted means of selected water quality variables measured concurrently with the collection of diatom samples containing Craticula pampeana.
Credit/Source: Montana Diatom Database