TRIANDRIA. 13 



10. Phalaris. Ca/.oftwo rather unequal valves containing a dou- 

 ble corolla. Seed* invested with the inner hardened corolla. 



11. Phleum. Cal. of 2 valves, valves nearly equal, acuminate 

 dv mucronato-aristate, including a single awnless corolla. 

 Seed free. 



12. Milium. Ca/. of 2 valves, valves ventricose. Seed invested 

 with the permanent hardened corolla. 



13. Agrostis. Cal. of 2 valves, valves acute, compressed, awn- 

 less. Cor. shorter than the calyx, slightly hairy at the base. 

 Seed free. 



14. Arundo. Cal. of 2 valves (in J. Thragmites many-fl.). 

 Cor. surrounded with long hairs. Seed free covered with the 

 corolla. 



31. RoTTBOLLiA. Ca/. of 2 valvcs, valves lateral. F/ciu^W5 alter- 

 nate, ranged upon a jointed rachis. 



t1' Flowers poh/gamous. 

 30. HoRDEUM. Cal. in threes, 2-valved, valves lateral, inter- 

 mediate ones perfect ; lateral ones with Anthers or Pistil. Cor. 

 2-valved, awned. 



** Calyces 2- or rarelij 3-floicercil. 

 t Floicers perfect. 



17. AiRA. Cal. of 2 valves, unequal. Cor. 2-valved, the out^r 

 one awned above the base (rarely awnless). Florets without 

 any imperfect ones between them. Seed free, but covered with 

 the Cor. 



18. Melica. Cal. of 2 valves, about 2-flowered, with the ru- 

 diment of a third floret. Cor. 2-valved, awnless. Seed free, 

 covered by the cartilaginous Cor. 



ft Floii'ers poh/garnoiiS. 



15. HoLCUS. Cal. of 2 valves, 2-flowered. Cor. 2-valved. 

 Anther- bearing floret awned. Seed free, or enveloped in the 

 membranaceous Cor. 



16. HiEROCHLOEf. Cal. of 2 valves, 3-flovvered. Cor. of 2 

 valves: the lateral Jlorets iThndrows ; pistil 0; terminal (ov 

 central) one perfect, diandrous. Br. in Prodr. Fl. Nov. Holl. 



*** Calyces many-floivered. 



fFlov:ers all perfect, or upper florets only sometimes imperfect J 



t Calyx of 1 valve. 



28. LoLiUM. Ca/. lateral, fixed. Cor. 2-valved, firmly en- 



* In all the Grass tribe I use the almost universally adopted term of Seed 

 for Fruit. This fruit is of that kind called a Caryopsis, which is when the 

 seed is intimately united v/ith the pericarp so as to form apparently but one 

 piece with it. 



f " Genus distincti^iimum, plurcs species tompleclcus, in fn^idis hc- 

 misphsetici utrinque provenientes." Br, I. c. 



