144 CLASSIFICATION OF [CH. 
= Lachilla cylindrical. 
Festuca elatior. 
This is an important grass, and should be thoroughly mastered 
as a type of the boat-shaped “seed.” 
This, with Lolium, Agropyrum, other Fescues, and even some 
Bromes and Poas, will give trouble until the student thoroughly 
masters the importance of the minute characters of size, nervature, 
of the rachilla, awn, palea, &c. 
Festuca elatior, L. (var. pratensis) (Fig. 58). 
Palea ovate-lanceolate, five-nerved, slightly scabrid, 
with a slight membranous margin and cilia, rounded 
back, and no awn. 6—7°5 mm. long. 
Caryopsis oblong-obovate, somewhat flattened, hardly 
grooved and adhering to the palee, about 3—3°5 mm. 
long. 
Rachilla cylindrical, smooth. 
The other varieties of F. edatior cannot be distinguished by the 
“seed” alone: in my samples /. elatzor proper is longer than 
F. pratensis, and both have occasionally a trace of awn. Var. arun- 
dinacea has a more acuminate, stiff point. Festuca pratensis has 
its palea as a rule somewhat more acute than Loliwm perenne, and 
the flatter tapering rachilla of the latter is more closely appressed to 
the palea. The caryopsis of Festuca also tends to adhere to the 
paleze. 
©@® Palee and “seed” at most 3—3'5 mm. long. 
= Palea devoid of hairs or keel, notched or 
blunt, and with no trace of awn. 
A Palea hyaline, nerves indistinct. Tips 
notched or blunt. 
Agrostis alba. 
There is occasionally a very short basal hair (awn). 
Agrostis and Aira will present difficulties to the beginner, not 
only on account of their small sizes, but also from the variability as 
regards awns, basal hair-tuft, &e. None are of value, and most of 
them are weeds. 
