Plants and their ways in South Africa . gles form ^rc^/Z^wc^j^^ resin gland (r) may be seen in the parenchyma. The innermost layer {e\ theendodertnis or starch sheath, contains starch. S, Stele or central cylinder con-taining one fibro-vascular bundle. {Pc), pericycle: it forms a cluster of scleren-chymatous cells just outside each bundle. Between these cells and the bundlecambium {fc) (fascicular cambium) lies the phloem. The portion of the bundleinside the cambium is the xylem. It contains row^s of large thick-walled woodvessels, (w) Medulla or pith, [ifc) Interfascicular cambium. can be
Plants and their ways in South Africa . gles form ^rc^/Z^wc^j^^ resin gland (r) may be seen in the parenchyma. The innermost layer {e\ theendodertnis or starch sheath, contains starch. S, Stele or central cylinder con-taining one fibro-vascular bundle. {Pc), pericycle: it forms a cluster of scleren-chymatous cells just outside each bundle. Between these cells and the bundlecambium {fc) (fascicular cambium) lies the phloem. The portion of the bundleinside the cambium is the xylem. It contains row^s of large thick-walled woodvessels, (w) Medulla or pith, [ifc) Interfascicular cambium. can be made out by their larger size. Iodine stains their con-tents, and those of neighbouring cells, yellow brown. Within the ring of bundles, the ground tissue making upthe greater portion of the stem is known as the medulla or pith,and between the bundles the medullary rays extend out to thecortex. They carry material from the wood out to the cortex Stem and Root Structures 73 where it is elaborated and returned to the bundle for distribu-. tion ; some is carried to the pith where it may be rays thus serve in horizontal distribution as the 74 Plants and their Ways in South Africa bundles serve for the vertical distribution of food and foodmaterial. Starch is also stored here. The cells outside of the bundles and within the endodermiscomprise the pericycle. This consists of several layers ofcells ; those just outside the phloem being developed into thick-walled fibres serving as a protection to the delicate cells ofthis tissue. The fibres stain with iodine nearly the same colouras the wood. They are sometimes called phloem- or bast-fibres, but they are not developed from the same region as thebundles. Between phloem and xylem the delicate cambium cellsare found. Some distance below the tip of the stem, the cellsof the medullary ray become active and by their division formcambium (interfascicular cambium) which unites with the cam-bium of the bundle and forms a compl
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectplants, bookyear1915
