Pharmaceutical botany, with glossary of botanical terms by Youngken Heber W. (Heber Wilkinson) 1885-1963

Author:Youngken, Heber W. (Heber Wilkinson), 1885-1963
Language: eng
Format: epub, pdf
Tags: Botany -- Dictionaries, Botany, Medical
Publisher: Philadelphia, Blakiston

Between each nbro-vascular bundle and the tip of each rib will be found a zone of collenchyma cells. In the mesocarp between each two ribs on the dorsal side occurs a single mtta or oil tube which is lined with a layer of brownish polygonal cells. These vittae contain the official oil of fennel. Two vittae generally occur in the mesocarp of the commissural side although four are reported to have been found in this region of some fennel fruits.

3. Endocarp, a narrow layer of cells, transversely elongated, except over the regions of bundles where they may be seen elongated in several directions.

4. Spermoderm or Seed Coat, consisting of a layer of somewhat broadened epidermal cells attached to the endocarp and several layers of collapsed cells which are only well denned in the region of the rap he.

5. Endosperm, a central mass of more or less polygonal cells containing aleurone grains and oil globules. Each aleurone grain contains a rosette aggregate of calcium oxalate and one or two globoids.

6. Embryo, embedded in the endosperm of the upper region of the seed.

THE SEED

A seed is a matured megasorus (ovule) borne by the sporophyte of a spermatophytic plant, enclosing a megaspore (embryo sac) within which a fertilized egg of the succeeding gametophyte generation has segmented to form a new sporophyte plant. The purpose of the seed is to insure the continuation and distribution of the species/ Like the ovule, it consists of a nucellus or kernel enclosed by integuments, and the descriptive terms used are the same. The seed coats, corresponding to those of the ovule, are one or two in number. If but one seed coat is present it is termed the spermoderm. If two are present, the outer one is called the testa, and the inner one the tegmen. The testa, or outer seed shell, differs greatly in form and texture. If thick and hard, it is crustaceous; if smooth and glossy, it is polished; if roughened, it may be pitted, furrowed, hairy, reticulate, etc.

The testa may often present outgrowths or seed appendages whose functions are to make the seeds buoyant, whereby they may be dis-

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