154 _A TEXT-BOOK OF GRASSES 
194. The grass family and its subdivisions—The 
genera of plants are grouped into families, and these into 
orders and higher divisions of the vegetable kingdom. 
The grass family is called Poaceze or Graminee, and this 
with the Cyperacee (sedges) constitute the order Poales 
or Glumiflore. 
The term Poales is used for the order in the “North American 
Flora,’ the termination -ales being uniformly added to a generic 
stem to form the names of orders. Glumiflore is used by Engler 
and Prantl in their ‘‘Pflanzenfamilien.’’ Glumacez is used by Ben- 
tham and Hooker (‘‘Genera Plantarum’’) as the name of the series 
that includes Eriocaulee, Centrolepidee, Restiaceze, Cyperaceze and 
Graminez. The classification here adopted is in the main that of 
Bentham and Hooker (‘‘General Plantarum’) and of Hackel 
(‘“‘Pflanzenfamilien’”’). The latter author will be followed in the 
enumeration of the tribes. Although Hackel’s classification is in 
some respects artificial, it is on the whole the most natural arrange- 
ment yet proposed. 
The family Poacez has been divided for convenience 
into 2 series and 13 tribes. 
195. The 2 series of tribes—Modern agrostologists 
usually divide the genera of grasses into 2 series. The 
first series Panicoideze (or Panicaceze), the more highly 
developed or modified, is characterized as follows: Spike- 
lets with 1 terminal perfect floret and often a staminate 
or neutral floret below; an articulation below the spikelet, 
sometimes in the pedicel, sometimes in the rachis, some- 
times at the base of a cluster of spikelets, the spikelets 
falling away at maturity singly or in groups, or with 
portions of the rachis; spikelets usually more or less 
dorsally compressed, rarely laterally compressed. ‘The 
second series, Pooidee, is characterized as follows: 
Spikelets with 1 to many florets, the imperfect ones 
when present usually being above; rachilla often artic- 
