. Beginners botany. Botany. PHENOGAMS AND CRYPTOGAMS I8I (pkenogam signifying "showy flowers," and cryptogam "hidden flowers"), but the terms represent distinct ideas in classification. The cryptogams include three great series of plants — the Thallophytes or algae, lichens, and fungi; the Bryophytes or mosslike plants; the Pteridophytes or fernlike plants. Suggestions. —186. The parts cf a fern leaf. The primary complete divisions of a frond are called pinnae, no matter whether the frond is pinnate or not. In ferns the word "pinna" is used in essentially the same
. Beginners botany. Botany. PHENOGAMS AND CRYPTOGAMS I8I (pkenogam signifying "showy flowers," and cryptogam "hidden flowers"), but the terms represent distinct ideas in classification. The cryptogams include three great series of plants — the Thallophytes or algae, lichens, and fungi; the Bryophytes or mosslike plants; the Pteridophytes or fernlike plants. Suggestions. —186. The parts cf a fern leaf. The primary complete divisions of a frond are called pinnae, no matter whether the frond is pinnate or not. In ferns the word "pinna" is used in essentially the same way that leaf- let is in the once-compound leaves of other plants. The secondary leaflets are called pinnules, and in thrice, or more, compound fronds, the last complete parts or leaflets are ultimate pinnules. The dia- gram (Fig. 263) will aid in making the subject clear. If the frond were not divided to the midrib, it would be simple, but this diagram represents a compound frond. The general outline of the frond, as bounded by the dotted line, is ovate. The stipe is very short. The midrib of a compound frond is known as the rachis. In a de- compound frond, this main rachis is called the primary rachis. Seg- ments (not divided to the rachis) are seen at the tip, and down to li on one side and to tn on the other. Pinnge are shown at i, k, I, o, n. The pinna o is entire; n is crenate-dentate; i is sinuate or wavy, with an auricle at the base; k and /are compound. The pinna k has twelve entire pin- nules. (Is there ever an even number of pinnules on any pinna?) Pinna / has nine compound pinnules, each bearing several entire ultimate pinnules. The spores. —187. Lay a mature fruiting frond of any fern on white paper, top side up, and allow it to remain in a dry, warm place. The spores will discharge on the paper. 188. Lay the full-grown (but not dry) cap of a mushroom or toadstool bottom down on a sheet of clean paper, under a venti- lated box in a warm, dry place, A day lat
Size: 1238px × 2017px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjectbotany, bookyear1921
