. Contributions from the Hull Botanical Laboratory. Plants. 2901] CHA MBERLAIN—BOTR YCHIUM 395 deeply cut that the bipinnate condition is reached. We do not regard Botrychium as a similar case, but believe that the differences in the margins of B. obliquum and B. dissectum are more like the differences in the margins of the leaflets of Boivenia spectabilis and B. scrrulata, and like the differences in the leaf margins of Dloon edule and D. spinulosum. In these four cycads, the margins are so constant that they are reliable diagnostic characters. The short subterranean stem, with the long-stalk
. Contributions from the Hull Botanical Laboratory. Plants. 2901] CHA MBERLAIN—BOTR YCHIUM 395 deeply cut that the bipinnate condition is reached. We do not regard Botrychium as a similar case, but believe that the differences in the margins of B. obliquum and B. dissectum are more like the differences in the margins of the leaflets of Boivenia spectabilis and B. scrrulata, and like the differences in the leaf margins of Dloon edule and D. spinulosum. In these four cycads, the margins are so constant that they are reliable diagnostic characters. The short subterranean stem, with the long-stalked leaf and spore-bearing portion with a still longer stalk, is similar in B. obliquum and B. dissectum. The roots of B. dissectum are wrinkled and fleshy, like those of B. obliquum, and not at all like the slender roots figured in Britton and Brown's Illustrated Flora. In general, B. obliquum is a larger plant than B. dissectum. At Oberlin the largest plant of B. obliquum measured 35 cm. in height, with a leaf 20 cm. in width, and the spore-bearing part of the fertile spike 15 cm. long. While this is not quite up to the limit in size recorded for the species, it is very large, and most individuals are much smaller. One plant of B. dissectum measured 28 cm. in height, but this is exceptional. The usual size of B. dissectum is about two-thirds that of B. obliquum. The most suggestive difference between B. obliquum and B. dis- sectum is seen in the fertile spike. The sporangia of B. dissectum sometimes look uniform and perfect, but somewhat smaller than those of B. obliquum. The difference in size, where the sporangia seem to be perfect, may be seen by comparing A and D of fig. 9- However, most specimens show a considerable proportion of abortive sporangia which, even without sectioning, may be dis- tinguished by their smaller size (fig. 9, B and C). The figure of B. dissectum in Britton and Brown's Illustrated Flora is evidently. Fig. 8.—Leaflets from three plants of B. diss
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectplants, bookyear1895
