. The essentials of botany. Botany. PTBmhOPHYTA. 309 are all of one kind, and are borne in roundish spore-eases, Whioli are generally single on each leaf. The Club-mosses are common in the Appalachian 1-egion, Canada, and northwestward, and all but one of our spedies belong to the genus Lycopodium. Of these may be mentiohed the Common Chib- mosses (L. clavatum and L. complanatum) and the (Jrouud-plne (L. dendroideum), all extensively used ih Christmas decorations. 438. The Little Club-Mosses {Order Selaginellaoem) re- semble the foregoing, but are generally smaller and more Moss-like, and have
. The essentials of botany. Botany. PTBmhOPHYTA. 309 are all of one kind, and are borne in roundish spore-eases, Whioli are generally single on each leaf. The Club-mosses are common in the Appalachian 1-egion, Canada, and northwestward, and all but one of our spedies belong to the genus Lycopodium. Of these may be mentiohed the Common Chib- mosses (L. clavatum and L. complanatum) and the (Jrouud-plne (L. dendroideum), all extensively used ih Christmas decorations. 438. The Little Club-Mosses {Order Selaginellaoem) re- semble the foregoing, but are generally smaller and more Moss-like, and have (-with few exceptions) four-ranked leaves. Their spore-cases occur singly on certain more or less modified leaves, which are clustered into terminal spikes. The spores are of two kinds; the small ones, which are very numerous, are generally borne in spore-cases in the upper part of the spike, while the larger ones (macrospores) are mostly four in each spore-case in the lower part of the spike (Fig. 118). 439. The first stage of the Little Club-mosses is almost ob- literated. When a small spore germinates, it becomes divided internally into a considerable number of cells, one of which appears to represent the first stage (prothallium), while all the rest form one large antherid, each cell of which pro- duces an antherozoid. 440. The large spore likewise produces a very small growth, which in this case, however, protrudes a little from the ruptured spore-wall. Upon this several archegones de-. FiQ. 119.—Plantlets of a Little Club-moss (Selaginella martensii), showing cotyledons. /, two plant- lets growing from one spore; p, the first stage (prothallium). //, a plantlet separated from the spore; r, robt; /, a structure called the "; Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original
Size: 1784px × 1400px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectbotany, bookyear1884
