CHARACEAE PLATENSES 227 



Montevideo, Oct. 1875, Igt et mst 01. J. Arechavaleta (sub 

 n. 302). 

 Obs. E nodulo radicali, difformi, hyalino-radicoso, párvulo (5mllm. 

 diam.) caulis simplicissimus exsurgens, erectus v. incurvatus, 

 nudus, 1-cellularis (3-5 cent. long. = 1,5-2 mllm. crass.), ápice 

 nodoso-verticilliferus atque abrupte ramoso-comatus, coma den- 

 siuscula circumscriptione ovata v. bemispbaerica (8 - 25 cent, 

 diam.); rami fere omnes aequilongi v. centrales sensim parceque 

 longiores, crassi, 4-6-articulati, articulo Ínfimo omnium lon- 

 gissimo (2,5-8 cent. loug. = 1,5-2 mllm. crass.), mediis gra- 

 datim abbreviatis, apicalibus brevissimis, simplices v. ad nodos 

 1-pluri-ramulosi, recti v. saepe incurvi. Verticilli steriles ad 

 nodos ramorum ramulorumque, saepius 8-foliati; eorum folia 

 máxima, teretia, crassa (2,5-9 cent. long. — 1,3- 1,5 mllm. 

 crass.), viridia, tenuissime sordideque incrustata, basi saepius 

 bistipulata, atque ad axillam saepissime ramulo evoluto v. abor- 

 tivo atque foliiformi donata, dimorpba: forma primaria, sim- 

 plex, elongata, 3-articulata, articulo Ínfimo longissimo, supremo 

 abbreviato; forma secundaria, elongata, 3-4 articulata, articulo 

 ínfimo saepius abbreviato, ápice foliolis 2-majusculis, elongatis, 

 saepe 2-cellularibus (1-2 cent. long. = 0,8 mllm. crass.) ornato, 

 secundo elongato, supremo iterum abbreviato; folia ac folióla 

 ápice obtusa, ac fere semper segmentulo additionali, mucroni- 

 formi, obtuse acutato, minuto (0,25-0,40 mllm. long. =z 0,1 5- 0,25 

 mllm. crass.), 1- v. 2- cellulari armata. Stipulae in verticillis 

 superis nonnumquam deficientes, et in intermediis ad 1 inter- 

 foliarem reductae, 2-cellulares, articulo infero duplo quam 

 supero, majusculae (1-2 cent. long. — 1 mllm. crass.), subflacci- 

 dulae. Verticilli fértiles 2-3-capitulato-constipati, capitulo ses- 

 sili v. pedicellato, solitario v. 2- 5- nato ad axillam foliorum 

 verticillorum superiorum, foliis 8-10-nis, ómnibus isomorphis 

 (vix magnitudine variantibus, in verticillis posticis elongatis, in 

 anticis abbreviatis 1,5-3 cent. long. = 0,40 -0,50 mllm. crass.), 

 flaccidulis, 4-5-cellularibus, articulo Ínfimo et supremo abbre- 

 viatissimis, secundo supero omnium longiore, ápice mucrone 

 l-(rarius 2-) cellulare, obtuse acutato aucta; ad geniculum in- 

 ferum 2 folióla (3 mllm. long.— 0,25 mllm. crass.), 3-cellularia 

 ápice mucrone 1-3-cellulare armata, atque genitalia gerentia; 

 folióla 1, v. rarius amba, saepe etiam fructífera ad nodulum 

 posticum, foliololis 2-cellularibus minimis (1 mllm. long. rz 



