— 28 — 



vaiva externa 2-5-dentata, dentibus irrefrulariter aristatis vel muticis, inteina 

 2-furca aut lacero-dentata: caryopsis libera, valva corollina interna , cincta. 



69- ECHINARIA Desf- Flores polygamo-monoici in capitulum echina- 

 tum, spiculis sub-2-fIoris, flore altero hermaphrodito, altero masculo aut ste- 

 rili: perigonii gluma calycina membranacea 2-vaIvis brevis , valvis apice 2- 

 lobis 1-rostratis, exterioribus quandoque 2-rostratis, valva externa in spicu- 

 lis superioribus 2-6-rostrala, interna 3-rostrata, gluma corollina cartilaginea 

 2-vaIvis, valva externa majore apice truncata, rostris 5-7 digitato-rostratis. 

 circa internam 2-rostratam , convolutis: squamae nectariferae 2 tiuncatae: 

 caryopsis libera, stylis persistentibus, coronata. 



70- TRIODIA Brown. Flores, spiculae oblongac cartaceae , in panicula 

 stricta: perigonii gluma calycina 2-valvis, spiculis, subaequalibus, valvis acu- 

 minatis, gluma corollina 2-vaIvis, valva externa majore ovata, basi utrinque 

 fasciculo pilorum barbata , apice 3-denticulata: squamae nectariferae 2 di- 

 stinctae: caryopsis libera, valvis corollinis persistenlibus occultala. 



71. AVENA L. Flores in panicula racemo vel spica, spiculis nitidis ma- 

 gniludine variis: perigonii gluma calycina communis 2-vaIvis mutica, valvis 

 margine et apice membranaceis: gluma corollina 2-vaIvis alterna distica nuda, 

 vel axe et interne barbata, valva externa majore apice 2-fida vel 2-dentata 

 saepe 2-seta, dorso aristata, arista geniculata infra geniculum contorta, valva 

 interna mutica 2-fida vel 2-dentala: squamae 2 nectariferae: caryopsis oblon- 

 ga libera, aut valvis corollinis inclusa. 



72. POA L. Flores spicati mutici in panicula vel racemo, rachide fle- 

 xuosa: perigonii gluma calycina communis 2-valvis, spiculis subaequalis: co- 

 rollina 2-valvis allerna distica libera aut villo connexa, suprema interdum 

 abortiva, valvis inaequalibus margine membranaceis, externa carinata, inter- 

 nam linearem pllcatam, includens: squamula nectarifera 2-fida vel 2 appro- 

 xitnatae: caryopsis libera, valvis corollinis, inclusa. 



73. BRIXA L. Flores mutici in panicula laxa, spiculis nitidis cordato- 

 ovatis turgidiusculis: perigonii gluma calycina, spiculis multo brevior, valvis 

 concavis in anthesi patentibus : gluma corollina 2-valvis , valvis admodum 

 inaequalibus muticis, externa major navicularls cartilaginea , margine pellu- 

 cido, inlerna minima ovata, margine inflexo , basi ovarii adhaerens: squa- 

 mae nectariferae 2: caryopsis 2-rostris, valvis corollinis, cincta- 



74. CYNOSURUS L. Flores in racemo composito secundo , racemulis 

 subdicotomis: spiculae pauciflorae secundae, valvis solitariis (potius bracteis) 

 alternis disticis muticis aristatisque, tectae: florum fertilium, perigonii, gluma 



