[Proc. Rot. Soc. Victoria, 29 (N S.), Part II., 1917]. 



Akt. XiV. — A Disease or Teratological Mai for mat ion of 

 Lucerne. 



By ELLINOR ARCHER, B.Sc. 



(With Plate X.). 

 (Read December 14th, 1916). 



Description of Abnopmality. 



The curious malformation about to be described was found on two 

 specimens of lucerne received from different parts of Victoria, one 

 being from the Werribee Irrigation Settlement, and the other from 

 Echuca. They had both been collected in February, 1916, which 

 was an exceptionally dry month. 



The only parts to be affected by the deformity are the flower 

 heads. The main stalks and the leaves are all normal, except a few- 

 small leaves at the termination of the main stalk, which show the 

 terminal leaflet very much elongated in proportion to the lateral 

 leaflets. The lower leaves and stem show symptoms of rust, caused 

 by Uromyces striatus, but this is hardly likely to have any con- 

 nection with the malformation. 



The place of true flowers has been taken by clusters of small, 

 indefinite heads, which show no special structure until they are 

 examination microscopically. 



These heads, as far as could be judged from the dried specimen, 

 were dull grey in colour, with a faint suggestion of the purple 

 characteristic of normal flowers. 



If each head is taken to represent a flower, the inflorescence will 

 be found to have increased in complexity from a simple raceme to 

 a raceme of racemes which may be several times compound. 



The main axies are normal, but the secondary are somewhat 

 elongated, and bear still smaller axies instead of forming the 

 peduncles of the flowers. The bracts to tlie main and secondary 

 axies are normal. 



Microscopic examination of the heads shows these axies to be 

 terminated by masses of rounded growing points, which are en- 

 veloped by what may be described as small, narrow, simple bracteate 

 leaves. Apparently all the growing points ultimately develop into 

 these abnormal leaves, there being no true flowers or rudiments of 

 parts of flowers to be found on either specimen. 



