254 GRAMINE.E. 



Grasses are widely (listribiited I'loni eijiiatorial toaretic rc^'ions, some genera especially abuinlant 

 in the troi)ies, but tiio majority belonging' to the temperate zones. In the nunxber of individuals 

 tliey probably exceed all oilier llinvrrinj,' plants, while in the number of species the family stands 

 third, the first and second places l.elonj;in<,' to CninposUtv. and Laiiuninosic. In nsel'ulness to 

 man they easily take the first rank, as ihey are at the foundation of all agriculture, their herbage 

 atfording the larger share of the fooil of animals, while their seeds supply, in the cereal grains, 

 the chief food of the world. Kice, Dnrra, Maize, Wheat, l{yc, Oats, Harley, and Sngar-("ane, 

 need only to be mentinncd to show the economical importance of the family. It is a singular fact 

 that the most useful of the family, tho.se which furnish the cereal giains, are none of them known 

 with certainty in the wild state, even their native countries being in doubt. Uut few grasses 

 present marked properties. Anthoxanthuvi, Jlieruchloc, and a few others, have a pleasant Va- 

 nilla-like odor, due to a principle like cuumarin. Some oriental si>ecies of Andropoijon ali'onl in 

 their foliage the oils of Lemon-Grass, Citronella, and Geranium, and from the roots of another 

 species is obtained the perfume " N'^ettiver." The rhizomes of Triticum re))ens and of Ci/nodou 

 Dactylon liave long had a reputation for usefulness in diseases of the bladder. The many u.ses 

 which the steins of si)ecies of Bambusc, the Hamboos, are made to serve in China and other eastern 

 countries give them a high rank among the useful grasses. In ornamental gardening, besides 

 furnishing the carpet of verdure without which our gardens would lose nnich of their attrac- 

 tiveness, grasses play an important part. From the humble Fcstnai ijlanai, the striking blue 

 foliage of which is used for eilgings, up to the stately Gijacriuin ai<j:iUcum, the Pampas-Grass, 

 the list of ornamental species and varieties is a long one. 



In describing the structure of the spikelets, both Bentliam and Hooker make n.se of difTereiit 

 terms from those here given. They designate the (jliunca as "empty glumes," and the lower pnlct 

 as the " llowering glume," while they have but a single " palet," which is our upper paid. The 

 usual terminology is here followed, as the one universally taught in our text-books, and as not 

 involving any theoretical views of the structure of the llowers. In the grouiiiug of the genera of 

 this immense family into subgenera, or into tribes and subtribes, botanists diller widely, accord- 

 ing to the prominence given by the authors to i)ailicular characters. The arrangement here 

 presented is not made to express any views as to the rehttioMshi|) of the genera, but solely with 

 the object of leading the student to the genus by the most direct path. 



Tkibe I. rANICACE.E. Spikelet articulated with the ])edicel below the glumes, mostly 

 2-flowereJ : one llower fertile ; the staminate or barren lloret, when present, below it. 



Subtribe I. PANICE/E. Spikelets of one terminal perfect floret with an imperfect (stami- 

 nate or neutral) one below it, the latter often reduced to a single palet ; .sometimes apjiear- 

 ing as if 1-llowered by the suppression of the lower glume and the upper palet of the neutral 

 floret. Grain incloseil in the coriaceous or chartaceous palets of the perfect lloret. 



» Spikelets apparently 1-flowered by absence of the lower glume, the palet of the neutral fioret 



taking its place. 



1. Paspalum. Spikelets plano-convex, on one side of a flattened rhachis. 



» ♦ Spikelets 1|- or 2-flowered : lower floret staminate or neuter, of 1 or 2 palets. 



2. Panicura. Spikelets without an involucre. Lower glume usually minute. 



3. Setaria. Spikelets with an involucre of bristles proceeding from the pedicels. 



4. Cenchru8. Spikelets inclosed, 1 to 3 together, in a hard bristly or spiny bur-like involucre. 



Subtribe II. ANDliOPOGONE.E. Spikelets in pairs, very dissimilar, one rudimentary. 

 Palets of the fertile floret scarious, thinner than the indurated glumes. 



5. Ischaemum. Spikelets on one side of a single spike. 



TuiisF. II. PHALAUIDE.E. Spikelets not articulated below the glumes, of one terminal j.er- 

 fect Hower, or with two male or neutral or rudimentary florets below the perfect one. 

 Spikelets laterally compressed. Glumes sometimes united below. 

 • Glumes wanting : inflorescence iJanicled. 



6. Leersia. Siiikelets much flattened. Palets rigid. Stamens 1 to 3 or 6. 



♦ ♦ (ilumes ])resent. 

 +- Spikehits l-llow(!red, densely spiked : glumes eipial, boat-.shaped, strongly keeled. 



7. Alopeciirus. (Jlumes united at base. Lower jmlet awm-d, upper wanting. 



8. Phleum. Glumes distinct. Lower palet uwidcss, upper present. 



+- +- Spikelets 1- 2-flowered, ]ianicled. 



9. Beckmannia. Spikelets (ours 1 -flowered) crowded in two rows upon the branches. 



-1- -1- -i- Spikelets 3-llowered, the lateral staminate or neutral : plant sweet-scented. 



10. Hierochloe. Lateralflorets staminate. Panicle loose. 



11. Anthoxauthum. Lateral florets neutral, of a .single awned hairy palet. 



