127 



GRASS FAMILY. 



4. Ixophorus Italicus (L,.) Nash. Italian Milk-t. 



(Fig. 283.) 



Panic it m Italicum I,. Sp. PI. 56. 1753. 

 Setaria Italica R. & S. Syst. 2: 493. 1817. 

 Chamaeraphis Italica Kuntze, Rev. Gen. PI. 768. 1891. 

 f.ivp/iorus Italicus Nash, Bull. Torr. Club, M: 423. 1895. 



Culms erect, 2-5 tall. Sheaths smooth or scab- 

 rous; leaves 6'-i or more in length, X'-iJ^' wide, 

 generally scabrous; spikes 4'-o/ long, l / 2 '-2 f thick, 

 usually very compound; spikelets about \%" long, 

 elliptic equalled, or exceeded by the upwardly barbed 

 generally purplish bristles; first scale less than one- 

 half as long as the spikelet, i-3-nerved; second and 

 third 5~7-nerved; fourth scale equalling or somewhat 

 exceeding the second, finely and faintly transverse- 

 rugose, or pitted, striate, only moderately convex; 

 palet of third scale minute or wanting. 



In waste places, escaped from cultivation, Quebec to 

 Minnesota, south to Florida and Texas. Native of tin- 

 Old World. July-Sept. 



i 4 . CENCHRUS I,. Sp. PI. 1049. 1753. 



Annual or perennial grasses with usually flat leaves. Inflorescence in spikes. Spike- 

 lets subtended by a spiny involucre which is deciduous with them at maturity. Scales 4; 

 the first hyaline; the second and third membranous, the latter sometimes having a palet 

 and staminate flower in its axil; the fourth chartaceous, subtending a palet of similar struc- 

 ture which encloses a perfect flower. Stamens 3. Styles united below. Stigmas plumose. 

 Grain free, enclosed in the scales. [Ancient Greek name for some grass, probably M 



About 12 species, in tropical and temperate region>. Ik-sides the following, some 4 other* 

 occur in the southern parts of North America. 



i. Cenchrus tribuloides L. Bur-grass* 

 Hedgehog-grass. (Fig. 284.) 



Cenchrus tribuloides L. Sp. PI. 1050. 1753. 

 Cenchrus Carolim'aniis Walt. HI. Car. 79. 1788. 



Culms erect or decumbent from an annual root, 

 usually robust, 8'-2# long, branching freely. 

 Sheaths usually very loose, compressed, smooth; 

 leaves 2^-5' long, 2" 4" wide, flat or somewhat 

 complanate; spikes I'-z/i' long, sometimes par- 

 tially included in the upper sheath; involucres 

 crowded on the scabrous rachis, 2-flowered, glo- 

 bose, pubescent except at the base, forming spiny 

 burs, the spines stout; spikelets about 3" long. 



On sandy stmu-s and in wa.-ti- places, MaineaiKl O 

 tario to Minnesota, -<>mh to l-'londa, (. 

 Texas. Sotm-titm- a noxious weed, 

 ennial in the Southern States. Anjr.-Sept. 



15. ZIZANIOPSIS Doell & Aschers. in Mart. Fl. Bras. 2: Part : 



Tall aquatic monoecious grasses, with long flat leaves and paniculate j, 

 Spikelets i-flowered, the staminale borne at the top of the branches, 

 base. Scales 2, nearly equal, membranous, the outer one m the pist 

 acute and bearing an awn. Stamens 6. Styles united. Grain nearly K lobot 

 readily separable. [Name in allusion to the resemblance o 

 A monotypic genus, of temperate and tropical America. 



