taxonID	type	description	language	source
038F9D50FF915E4BFF38528AFE0F1248.taxon	description	SEM: — In external valve view, areolae are simple and transapically oblong (Figs 25, 26). Occlusions and secondary structures (e. g., vimines) are absent. Striae continue around the valve apices (Fig. 26); apical pore fields are absent. Costae between striae are wide relative to the striae themselves. External raphe fissures are narrow, becoming much wider at the terminal fissures (Fig. 26). Internally, areolae are arranged end-to-end in trough-like alveoli and separated by narrow intercostae (Figs 28, 29). Internal raphe fissures are wide, narrowing towards the terminal and proximal ends. Raphe branches terminate in simple helictoglossae (Figs 27, 29). Proximal raphe ends are hooked and separated by a wide intermissio (Fig. 28). A flap of silica with a curved edge overlies the central nodule on one side and merges with it at its center (Fig. 28). Holotype: — USA, Montana: East Fork O’Dell Creek, fen pool no. 4, 1567 m a. s. l., 45.2743 ° N, - 111.2750 ° W, 24 July 2017, coll. Tara Luna, Slide No. 49 - 69, MONTU! Holotype specimen is in Fig. 5. Isotype: — Slide No. 136 - 34, Montana Diatom Collection (MDC), Helena. Paratype: — USA, Montana: East Fork O’Dell Creek, fen pool no. 2, 1567 m a. s. l., 45.2738 ° N, - 111.7255 ° W, 24 July 2017, coll. Tara Luna, Slide No. 49 - 67, MONTU!, Slide No. 136 - 32, Montana Diatom Collection (MDC), Helena. Differential diagnosis: — The species most similar to C. laszlorum in North America is C. stauroneiformis (Lagerstedt) Krammer (2003: 86), an Arctic species described from Spitsbergen (Figs 13 – 19). The two species have very similar morphometric values and both have central areas in the shape of a fascia, however C. laszlorum has wider (10 – 12 μm vs. 8 – 11 μm) and more elliptic valves with wider apices (Table 2). Other North American species of Cymbopleura, including C. geofriedana Reichardt (2004: 428) and C. tynnii (Krammer) Krammer (2003: 30), have similar valve and end shapes as well as comparable striae and areolae densities (Figs 20 – 23, Table 2), however Cymbopleura geofriedana (Fig. 20) is much smaller (17 – 30 μm long) than C. laszlorum (41 – 54 μm long) and C. tynnii (Fig. 23) is much larger (48 – 94 μm long). Two undescribed taxa from Kazakhstan and the Swiss Alps (Figs 21, 22) have wider (13 – 15 μm), more elliptic valves than C. laszlorum, but otherwise similar shapes, central areas and stria densities (Table 2). The taxon from Kazakhstan (Fig. 21) appears to be conspecific with Cymbopleura mongolica Metzeltin et al. (2009: 30), which has valves with comparable shape and morphometrics (Table 2). The taxon that most closely resembles C. laszlorum lives at 4800 m a. s. l. in the Everest region of Nepal: Cymbopleura cf. mongolica (Van de Vijver et al. 2011: 257). This taxon differs from C. mongolica by its smaller dimensions (10 – 11 vs. 12 – 14 μm wide) and slightly higher stria density (17 – 19 vs. 15 – 17 in 10 μm). It differs from C. laszlorum by the shape of the ends, which are subcapitate rather than rostrate, and by a higher areola density (30 – 35 vs. 20 – 30 in 10 μm) (Table 2). All of the taxa discussed above are from boreal or alpine habitats in the northern hemisphere. Diatom associates: — At the type locality, Cymbopleura laszlorum was an uncommon (<1 % abundance) but visually conspicuous element of a benthic diatom association dominated numerically by Mastogloia lacustris (Grunow) Grunow in Van Heurck (1880: 70), Cymbopleura florentina (Grunow) Krammer (2003: 99), and Epithemia argus (Ehrenberg) Kützing (1844: 35), in decreasing order of abundance. Etymology: — The new species is dedicated to the Jeff Laszlo family for its steadfast stewardship of this rare and invaluable wetland resource.	en	Bahls, Loren, Luna, Tara (2018): Cymbopleura laszlorum spec. nov. (Cymbellaceae, Bacillariophyceae), a glacial relic from a calcium-rich floodplain fen in southwestern Montana, USA. Phytotaxa 349 (1): 47-53, DOI: 10.11646/phytotaxa.349.1.5, URL: http://dx.doi.org/10.11646/phytotaxa.349.1.5
