PLANTS OF SOUTHERN NEW JERSEY. 319 



Diffenbaiigh." given in Dr. Britton's Catalogue. We have been 

 unable to verity this record or to locate the original specimens. 



WOLFFIA Horkel. 



Wolffia Columbiana Karst. Columbian Wolffia. 



Wolffia Columbiana Karsten, Bot. Unters I. 103. 1865-67 [no locality given]. 

 Willis 59. — Britton 255.— Keller and Brown 90. 



Middle district, extending to Bergen County. 



The little g'reen discs of the Duckweed, with their slender 

 rootlets hanging beneath, reproducing by branching and separa- 

 tion from the parent disc and rarely found blossoming, seem far 

 enough removed from our conception of a flowering plant, but 

 the still more minute JVolffia is the extreme in this direction. 

 The plants consist of minute green globules about a millimeter in 

 •diameter, which float just below the surface of the water. 



Middle District. — Fish House, Kaighns Pt. (C), Bridgeport, Pedricktown 

 (H), Jumbo (H). 



Order XYRIDALES. 



Monocotyledenous herl)s, flowers usually regular, parts in 3'3 

 ■or 6's. Ovary compound, superior. Endosperm of seed meal}". 



Family XYRIDACE.^. Yellow-eyed Grasses. 



Characteristic plants of the Pine Barren district. Three of the 

 six species occur sporadicallv in the Middle and Cape May dis- 

 tricts, and one other is restricted to the latter. 



The yellow flowers are quite showy, but only last a short time. 



XYRIS L. 



Key to tJic Species. 



a. Base distinctly bulbous thickened. 



b. Lateral sepals projecting beyond the bracts and fringed. 



X. arenicola, p. 322 



bb. Lateral sepals not projecting beyond the bracts and not fringed. 



Bracts tightly imbricated even when ripe, uniform chestnut, heads 



nearly spherical. X. torta, p. 320 



'Oa. Base not bulbous thickened. 



b. Lateral sepals projecting beyond the bracts. Plants large. 6-9 dm. 

 high, leaves 20 mm. broad. 



