ME. Q. BENTHAM Olf flEAMtNEjl. 29 



and accurately described in comparatively few species. The cha- 

 racters thus ascertained in a single one have been supposed to 

 belong necessarily to the whole genus ; and when differences have 

 afterwards been found in some other species, it has at once been 

 generically separated, without ascertaining whether these dif- 

 ferences might not be reconciled or connected through other 

 species. Before, therefore, we can ascertain the real generic 

 value of characters which cannot be tested in herbarium speci- 

 mens, it is necessary that we should have them well and authen- 

 tically described in a much greater number of species from 

 actual observation. I have on several occasions had reason to 

 believe that, in long-detailed descriptions drawn up by accurate 

 botanists from dried specimens, the seminal characters have been 

 rather guessed at on theoretical grounds, than actually verified on 

 really ripe seeds. 



Following out the views of General Munro as to the general 

 arrangement of the Order in as far as I have been able to ascer- 

 tain them, we have divided it into tribes and subtribes, of which 

 the following are the most prominent characters, omitting for 

 the present exceptional forms, which occur in almost all of 

 them : — 



A. Panicaceje. Spiculas cum pedicello infra glumas articulatse, 

 flore fertili unico terminali, addito interdum inferiore masculo 

 V. sterili. 



Tribus i. Pajiiceae. Spiculse hermaphroditse, rarius abortu unisexuales, 

 spicata; v. paniculatoe, rhachi infiorescentiae inarticulata. Gluma 

 florens exaristata, fruetifera indurata v. saltern exterioribus rigidior. 



Tribus ii. Maydeae. Spiculse unisexuales, masculBe terminales spicatse 

 V. paniculatse v. (in Pariand) foemineam circumdantes, foeminese in- 

 feriores spicatse, cum rhacheos internodio (excepta Zea) articulatim 

 secedentes. 



Tribus iii. Oryzeae. Spicula: hermaphroditae v. rarius unisexuales, pani- 

 culatse V. spicatse, rhachi inflorescentise inarticulata. Gluma sub flore 

 summa (palea ?) uninervis v. carinata. 



Tribus iv. Tristeginese. Spiculse hermaphroditse, secus paniculse ra- 

 mulos inarticulatos solitarise v. rarius geminse v. fasciculatee, cum 

 pedicello articulatse. Glumae vacuse aristatse v. muticae, florens hyalina 

 V. tenuiter membranacea, arista geniculata terrainata v. mutica. 



Tribus v. Zoysiese. Spiculae hermaphroditse v. nonnuUse imperfectas, 

 cum rhachi inarticulata spicse simplicis sigillatira v. fasciculatim ar- 

 ticulates. Gluma florens membranacea, saepius vacuis minor hyali- 

 uaque. 



LINlf. JOXJEN. — BOTANY, TOL. XIX. E 



