Elementary botany . 254 MORPHOLOG V. is termed the annu/us, which means a little ring. .While thisis not a complete ring, in some other ferns the ring is nearlycomplete. 534. In the front of the sporangium is another peculiar group. Rhizome of sensitive fern (Onoclea sensibilis). of cells. Two of the longer ones resemble the lips of some crea-ture, and since the sporangium opens between them they aresometimes termed the lip cells. These lip cells are connected withthe upper end of the annulus on oneside and with the upper end of the stalkon the other side by thin-walled cells,which may be term
Elementary botany . 254 MORPHOLOG V. is termed the annu/us, which means a little ring. .While thisis not a complete ring, in some other ferns the ring is nearlycomplete. 534. In the front of the sporangium is another peculiar group. Rhizome of sensitive fern (Onoclea sensibilis). of cells. Two of the longer ones resemble the lips of some crea-ture, and since the sporangium opens between them they aresometimes termed the lip cells. These lip cells are connected withthe upper end of the annulus on oneside and with the upper end of the stalkon the other side by thin-walled cells,which may be termed connective cells,since they hold each lip cell to its partof the opening sporangium. The cellson the side of the sporangium are alsothin-walled. If we now examine asporangium from the back, or dorsalUnder side of pinnaof Aspidium edge as we say, it will appear as in the spinulosum showing fruit dots . - . ~ TT (sori). left-hand figure. Here we can see how very prominent the annulus is. It projects beyond thesurface of the other cells of the sporangium. The spores arecontained inside this case.
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Keywords: ., bookauthoratk, bookcentury1900, bookdecade1900, booksubjectbotany
