IOWA ACADEMY OF SUIEXCKS. 85' 



value to our hot.inists and seedsmen. The key of Dr. Hirz is ^ood, Init it is too 

 general in its nature for our purpose. 13 jlow is offered a key designed e£pecially 

 for the uiontification ot weed seeds comunnly found in clover seed. Tnough rude 

 and incomplete, it may be of some service. 



Fruit not enclosed by a glume and palet; not a caryopsis. 



I. Acheties, sharply triangular. 



1. Black and shiny; sides concave; length, 1". 



Pohigoniiin acre, H. B. K. 



2. Black, but not shiny; usually enveloped by the close fitting calyx; sides 



not concave; length, \%-2" . 

 Folfjgoiuim convolriiJus, L. 



3. Brown and shiny; embryo peripheral. 

 a Not enveloped by calyx; length, 1". 



i Crispus, L. 

 Till HI ex. . . -\ 



i AUissimitfi, Wood. 

 b Usually closely enveloped by calyx; length, about }4" . 

 Rumex acetosella, L. 



4. Brown or light colored not shining; embryo central. 



Carex. 



5. Reddish black; not shiny; pointed; length, IJ^". 



Pohjgonum avicnlare, L. 



II. Achenes or nutlets, slightly triangular. 



1. An achene, nearly flat; one angle very obtuse and rounded; somewhat 



ovate; dull blaok; length, l.^a". 

 ''FoIi/goiiiiDi hgdrojjiper. L. 



2. Nutlet; brown; narrowly ovate; length, 1'; one face flat, the other two 



meeting in an obtuse angle which is bordered on each side by a line of 

 darker brown ; very smooth. 

 Bninella vulgaris, L. 



III. Achenes, lenticular or ovate and ilatteaed. 



1. Usually black; embryo'"' coiled in a ring around the albumen; never 

 more than 1" in length; not pointed at apex; sides convex. 

 a Shiuv black; without utricle. 

 * Orbicular; i-j" bi-oad. 



Amaranlus albus, L. 

 ** Somewhat ovate; length ^-s". 



Amarantus retroflexus, L. 

 *** Less shiny; orbicular; f-1" broad. 

 Amarantus blitoides, Watson. 

 b Dull grayish black; orbicular; utricle frequently present; J" broad. 

 Chenopodium album, L. 



■'lu the fjencra Polygonum and Rumex many achenes are found from which the pericarp 

 has been removed in tlirushiug. 6uoh are flesh colored and of the same shape as the achenes 

 before mutilation. 



"The pericarp is often partially removed in Amarantus &niX Clienopodium showing the flesh 

 «olored seed. The coiled embryo can be readily seen with a hand lens. Usually enough of t'ue 

 pericarp remains to identify the genus. 



