. The Canadian field-naturalist. . 5 mm Figure 5. Camera lucida drawings of sterile (below) and fertile (above) pinnules of Marsh Fern and Massachusetts Fern both from Newington Bog, Stormont Co., Ontario. veins works relatively well, but there is no need to rely upon it totally since a few other characters are at least equally useful. The basal pinnae of Marsh Fern tend to be broad based whereas those of Massachusetts Fern tend to be somewhat narrowed to the base (Figure 4). This is particularly evident in sterile fronds and seems to be a very useful character (Wherry 1961). In addition the p
. The Canadian field-naturalist. . 5 mm Figure 5. Camera lucida drawings of sterile (below) and fertile (above) pinnules of Marsh Fern and Massachusetts Fern both from Newington Bog, Stormont Co., Ontario. veins works relatively well, but there is no need to rely upon it totally since a few other characters are at least equally useful. The basal pinnae of Marsh Fern tend to be broad based whereas those of Massachusetts Fern tend to be somewhat narrowed to the base (Figure 4). This is particularly evident in sterile fronds and seems to be a very useful character (Wherry 1961). In addition the pinnae of Massachusetts Fern tend to be more long-acuminate (Figure 4). Although qual- itative, this also has proven to be a reliable character. Another good frond character of Massachusetts Fern is the more or less ascending and retrorse basal pinnae. The fronds frequently arch strongly, some- times becoming horizontal. While most of the pinnae are flat ( parallel to the surface of the ground), the two basal pinnae are tipped upward, often with an angle of less than 90° between them. As well as being ascending, the basal pinnae are retrorse, directed away from the other pinnae (as in Long Beech Fern (Phegopteris connectilis)) and downward when con- sidering the frond axis to be vertical. In pressing a frond to make an herbarium specimen, or when the arching frond is flattened, the retrorse character of the basal pinnae becomes more evident. Thus orientation of the basal pinnae is a useful character, especially in the field, and has been used in some texts ( Cobb 1956). No doubt this is what Davenport (1894) referred to as "one of those indefinable graces of appearance that sometimes gives character and tone to a plant just as a certain air or carriage oftentimes distinguishes one person from ; In some keys basal pinnae Vi to fully as long as the middle pinnae is used to separate Marsh Fern ( Please note that these images are extracted from s
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