LEAF-BASE PHYLLODES AMONG THE LILIACEAE 1 



Agnes Arb er 



(with FOUR figures) 



In a recent paper (i) the writer advocated the view that leaves 

 of monocotyledons have no true laminae, but are either equivalent 

 to petioles +leaf -bases, or are still further reduced until they reach 



the DOint of renresentinF leaf -bases alone. 



mainly 



In the paper cited. 



the present article it is proposed to review certain leaves among the 

 Liliaceae which seem to be of leaf -base or leaf-sheath nature, and 

 to consider the evidence upon which this interpretation is based. 



There are a number of leaves among different tribes of the 

 Liliaceae whose external appearance and general structure may 

 well be taken to suggest a leaf-base origin. They show no differ- 

 entiation into sheath and limb; they are parallel veined and 

 furnished with a single series of normally orientated bundles. As 

 examples Hemerocallis, Tulipa, and S cilia may be cited. That a 

 view which presupposes a considerable power of development on 

 the part of the leaf-sheath is not necessarily too extreme, is indi- 

 cated by the fact that in some monocotyledons, in which there is 

 a differentiation into sheath and limb, the sheaths may attain 

 remarkable dimensions. For instance, the sheath of Typha may 



meter loner (%). Aeain 



in which all the 



leaves are undoubtedly of leaf-base nature, namely, Oreomyrrhis 

 linearis Hemsley. The linear leaves of this species, which bear a 

 general resemblance to those of monocotvledons, terminate in a 



rudiment aDnarentlv reDresentiner the 



in 



Tulip 



We may 



in 



this theory. 



x This paper represents part of the work carried out during the tenure of a 

 Keddey Fletcher- Warr Studentship of the University of London, and with the aid 

 of a grant from the Dixon Fund of the University of London. 



3371 



[Botanical Gazette, vol. 69 



