Organography of plants, especially of the archegoniatae and spermaphyta . afy dendroideum(Fig. 39) has an obliqueascending shoot-systemwhich develops no rhi-zoids. These are foundupon shoots, bearing re-duced leaves, w^hich boreinto the substratum, andpenetrate it in all direc-tions, being externallyquite root-like. In manyspecies of Plagiochilaand Bryopteris (Fig. 40)the shoots in their lowerpart cling to the sub-stratum, and raise them-selves up as free struc-tures in their upper outer factors in-fluence the developmentof these forms of shootswe do not yet know. Lo
Organography of plants, especially of the archegoniatae and spermaphyta . afy dendroideum(Fig. 39) has an obliqueascending shoot-systemwhich develops no rhi-zoids. These are foundupon shoots, bearing re-duced leaves, w^hich boreinto the substratum, andpenetrate it in all direc-tions, being externallyquite root-like. In manyspecies of Plagiochilaand Bryopteris (Fig. 40)the shoots in their lowerpart cling to the sub-stratum, and raise them-selves up as free struc-tures in their upper outer factors in-fluence the developmentof these forms of shootswe do not yet know. Long shoots andshort shoots. Of other kinds of division of labour among the branches ofone shoot-system, apart from the supporters of the sexual organs, that oflong shoots and short shoots, which as is known also occurs in the thal-lose forms, must be mentioned. It is very distinct in Bryopteris filicina(Fig. 40). Tubers. The formation of tubers which takes place in some of thethallose Hepaticae, is unknown as yet in the foliose acrogynous forms (see,however, Fig. 39,^).. Fig. 39. Lembidium dendroideum. An isolated plant. The aerialshoot-system ascends obliquely with incun-ed ends. A, antheridial branchesat the base of the shoot-system. Root-like subterranean slioots pass down-wards on one of which is a tuber, B. The oldest aerial shoot is the brokenstump on the right. Magnified 4. ^ See p. 26- 44 VEGETATIVE ORGANS OF HEPATICAE Branching and the leaves. There remains to mention relationships ofthe branching to the leaves. In no case is branching axillary. The branchesare either lateral or ventral, in correspondence with the dorsiventral characterof the foliose Jungermannieae, just as in the thallose usually dorsiventralforms. In Anomoclada alone do the branches appear upon the dorsal sideof the shoots, and the branching in this genus requires further the lateral branching the formation of the branch takes place partly at the cost of onelateral leaf. A leaf, ofsay
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