THE MORPHOLOGY OF THE SEED OF BUCKWHEAT 
NEIL E. STEVENS 
(WITH EIGHT FIGURES) 
The Polygonaceae have been several times referred to in recent 
literature as being characterized by the production of seeds 
having an abundant perisperm (JOHNSON 7, p. 337; COULTER and 
CHAMBERLAIN 3, p. 179). This character has been taken by 
JoHNSON as an indication of rather close relationship between the 
Polygonaceae and the Piperaceae, in which family he has observed 
a perisperm. These statements as to the seed of the Polygonaceae 
are apparently based on the work of HArz (4, p. 1072), who includes 
this family among the “Curvembryonaten,” which he characterizes 
as ‘‘Eine grosse natiirliche Gruppe... . alle ausgezeichnet 
durch den Besitz eines reichlichen mehlhaltigen Perisperms und 
eines meist peripherisch gelagerten Embryo.”’ Harz (p. 1102) 
figures and describes in considerable detail the structure of the 
buckwheat seed, and evidently considers the entire storage region 
as perisperm. He also states that the same condition occurs in 
species of Rumex. KRAEMER (Q), to be sure, speaks of the Poly- 
gonaceae as having an endosperm, but does not discuss the mor- 
phology of the seed. 
A careful study of the seed of Fagopyrum esculentum has con- 
vinced the writer that in this genus at least no perisperm is present 
at maturity. The material used in this study was collected dur- 
ing the summer of 1910 and fixed in Juel’s fluid (JuEt 8). Micro- 
tome sections were used exclusively. These were cut rather thick, 
usually about 12, and stained with Delafield’s haematoxylin. 
The early development of the embryo appears to be typical in 
every respect. In fact, up to the stage at which the cotyledons 
begin to be differentiated, the embryo corresponds almost cell for 
cell with the often figured Capsella Bursa-pastoris, in which, how- 
ever, the suspensor is considerably longer. 
Free nuclear division apparently begins in the embryo sac soon 
after fertilization, and by the time the embryo has reached the 
* 59) [Botanical Gazette, vol. 53 
