l89I J Anatomical Characters of Uniola. 167 



Vesque, 2 who proved that the anatomical characters are much 

 more distinct and precise than the organographical ones, and 

 that species of Capparidece may be easily distinguished 

 merely by the structure of the leaves. 



To speak in particular of the Graniine<z\ we have several 

 works of the greatest importance upon this subject. Duval- 

 Jouve described 8 species of Agropyrum merely by the struc- 

 ture of the rhizomes, culms and leaves, and he stated in hi 

 "Histotaxie des feuilles de Graminees" 4 the principal modes 

 of arrangement of the tissues in the leaves of this family in re- 

 lation to the surrounding medium. 



Furthermore Hackel in his kk Monographia Festucarum Eu- 

 rop^earum' 1 (1882), has shown the importance of the leaf-struc- 

 ture as to the specific differences in Festuca. The same author 

 has also observed that most of the species of the Andropo- 

 gone^e ° show very good anatomical characters; and finally 

 Giintz 6 has made a special study of the leaf-structure. 



These studies are, however, not only of a purely scientific, 

 but also of a practical value, and it is easy to understand, that 

 they must be a great help, when it is necessary to identify 

 specimens without flowers. But that this may be done it will 

 be necessary to know the structure of a large number of 

 species. That such determination is possible to a certain ex- 

 tent will be evident if we simply recall the numerous differ- 

 ences in the form of the rhizomes, the sheath ligule and blade 

 of the leaves, the vernation, etc., which, combined with ana- 

 tomical characters, seem likely to give very reliable results. 

 A few attempts have already been made in the most practical 

 manner to identify Grasses at a stage where the flowers are 

 not developed, for instance by Samsoe Lund 7 and Beal. 8 



We now proceed to give some anatomical sketches of our 

 native grasses, making the beginning with the genus Uniola. 

 of which five species are enumerated from this country, namely: 



~ Essai d'une monographie anatomique et descriptive de la tribu des Cap- 

 Parees. (Ann. d. Sc. Nat. Botanique, ser. 6, vol. xiii. 1SS2). 



* Etude anatomique de quelques Graminees, et en particulier des Agropyrum 

 a * 1 Herault. (Mem. d. I" Acad d. Montpellier, vol. vii, 1870). 

 4 Ann. d. Sc. Nat. Botanique, ser. 6, vol. i. ISM. 

 A et C. De Candolle: Monographia Phanerog. Prodromi; vol. vi, 1889. 

 . * H E. M. Guentz: Untersuchungen ueber dieanatomischeStructur der Gram- 

 ^eenblaetter, etc. Inaug. -Dissert. Leipzig, 1886. 



7 Vejledning til at kjende Grosser i blomsterios Tilstand. Kjobenhavn, 1888. 



W, J. Beal: Grasses of North America for farmers and students, 1**T. 



