. The Canadian field-naturalist. 1995 Mann: Charophytes of Crooked Lake, Saskatchewan 425. Figure 6. Nitella sp. a: typical branchlet; b: variation in branchlet apices, scale bar = 1000 ^m. of some Chara axes. A thorough search of all collec- tions made from this site turned up no further Nitella specimens. The plant was entirely sterile, no gametangia were present. The thallus axis is very slender, only 215 urn in diameter and 20 cm in length with six branchlets per node. Dactyl apices are most- ly acute or acute-apiculate as described and illustrat- ed in Wood (1965) and Wood and Imahori (19
. The Canadian field-naturalist. 1995 Mann: Charophytes of Crooked Lake, Saskatchewan 425. Figure 6. Nitella sp. a: typical branchlet; b: variation in branchlet apices, scale bar = 1000 ^m. of some Chara axes. A thorough search of all collec- tions made from this site turned up no further Nitella specimens. The plant was entirely sterile, no gametangia were present. The thallus axis is very slender, only 215 urn in diameter and 20 cm in length with six branchlets per node. Dactyl apices are most- ly acute or acute-apiculate as described and illustrat- ed in Wood (1965) and Wood and Imahori (1964) (Figure 6b). From its once furcate branchlets, single- celled dactyls and acute dactyl apices, it most likely is Nitella flexilis or a closely related form. Dactyls are of unequal size as illustrated in Figure 6a. Both monoecious Nitella flexilis and dioecious N. opaca are cosmopolitan species and among the most commonly collected Nitellas. Because members of the N. flexilis complex can flourish over an extreme- ly broad range of environmental parameters (Olsen 1944; Langangen 1974), they should be frequently encountered throughout the area, especially so in the more oligotrophic northern lakes. Even though Wood (1965, 1967) treats these two as a single taxon, this approach may no longer be tenable and monoecious and dioecious taxa should be distin- guished whenever possible (Sawa 1965; Proctor 1975, 1980). If the opportunity arises, this site should again be thoroughly sampled in an attempt to obtain additional material on which to base a more sound taxonomic judgement. Other Charophytes Recorded From Saskatchewan The following records of Saskatchewan charo- phytes are those for which specimens are known to exist or which are otherwise considered to be well documented. The information may be of use to oth- ers involved in charophyte studies or in more general aquatic studies where charophytes are only one of the components being investigated. If taxonomic identity of these
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