496 Scientific Intelligence. 



Tous ces characteres indiquent leur nature petiolaire; mais les 

 fibres de ces petioles sont assez ecartees pour adrnettre un peu de 

 parenchyme, et pour porter des storaates; d'ou resulte que ces 

 organes jouent physiologiquement le role de limbe. Des trans- 

 formations analogues ont lieu dans quelques especes d'oxalis ; 

 telle est, par example, V Oxalis bapleurifolia, et l'Oxalis fruti- 

 cosa." 



The verticality is insisted on in both of these definitions, and 

 yet, species of Oxalis, in which the flattened petioles are not ver- 

 tical, are adduced as illustrations of phyllodia. Plainly the defi- 

 nition should be reconstructed, or the illustrations omitted. 



In the descriptions of the species of Oxalis given in The Flora 

 of Brazil,* Progel, the editor of the Order Oxalidese, uniformly 

 applies the term Phyllodium to the flattened petioles even where 

 they are not vertical, but lie in the same plane as ordinary leaves. 



If, now, we turn to the definitions of Phyllodium by another 

 author, Balfour, we shall see that the feature of verticality is not 

 insisted on as universal, but is regarded as a special case. 



In the "Class-Book of Botany" (Edin., 1854, p. 134), we find 

 the following : " In some Australian plants belonging to the 

 genera Acacia and Eucalyptus (sic) the petiole is flattened and 

 becomes a foliar expansion which occupies the place of true 

 leaves. Such petioles have received the name of Phyllodia. The 

 ti - ees bearing tliem give a peculiar character to some of the ior- 

 ests of New Holland. These phyllodia are usually placed verti- 

 cally presenting their edges to the sky and earth, and their 

 venation is parallel. Trees producing naked vertical phyllodia 

 only have a singular effect as regards light and shade. Travelers 

 have noticed this in some of the Australian forests .... Some 

 shrubby species of Wood-sorrel exhibit phyllodia which are either 

 naked or bear ternate leaflets. These phyllodia, are often placed 

 like leaves, with their flat surfaces towards the sky and earth.'''' 



Moreover, if we go back to the Theorie elementaire by DeCan- 

 dolle, a work published in 1813, we shall observe that the verti- 

 cality of the Phyllodium was not regarded as essential. The 

 following extract is taken from the second edition of the Theorie 

 elementaire, published in 1819 (p. 362) : 



Petiole foliac'e ou Phyllodium. — Je donne ce nom aux petioles 

 de certaines feuilles composees ou tres-decoupees, qui prennent 

 tellement d'extension, qu'ils semblent de veritables feuilles, et que 

 leurs folioles ou leur limbe avortent en tout ou en partie, par ex- 

 emple, dans les Acacies de la Nouvelle-Hollande ; cet accident se 

 presente aussi dans les feuilles submergees des Alisma et de la 

 Sagittaire ; il arrive peut-etre constamment dans celles des Bu- 

 pleures, etc. 



In view of this discrepancy it seems advisable to remove from 

 the definition of Phyllodium the restriction of verticality, and 

 apply the term Phyllodium to all cases of flattened petioles, where 

 there is great reduction of the blade. f 



* Flora Brasiliensis, (vol. xii, II, p. 515). f Ann. Bot., May, 1889. 



