47 



68. S. SPECIES indeterminnndu Hoolc. fil. 1. c. p. 172. 



Hab. in insula Albemarle {Macrce). 



3^. CENCHRUS. 



Linn. gen. u. 1149. Emil. gen. n. 783. 



69. P. PLATYACANTHUS Ands. : culmis adscendentibiLs; foliis scabris, vaginis glabris; invo- 

 lucro subtruncato, irregulariter emarginato, latere introrso ad basin fisso, extus un- 

 dique spinis planiusculis echiiiato, glabriusculo, spicnlis plerumque ternis subbreviore; 

 flosculo neutro unipaleaceo. — Ands. 1. c. p. 139. 



Hab. locis siccissiinis graminosis reg. media3 in insulis Chatham et Charles abundans 

 (Ipse). 



Culmi Cce.spitosi, .«implice,s, a ba.si breviter geniciilata ad.scendentes, erecti, pedales ve! ultra, compres- 

 .siusculi, glabri, flavo-iiiteiites ; iiodi augusti ob.seuri. Folia ob.scure viridia, anguste linearia, patentia v. .sub- 

 flaccida, acuta, plana, utriiique .secus nervös et margines scabra; vaginse longas, convolutae, glabrse, striatae, 

 internodiis paullo breviores; ligula brevis, truncata, fusco-fulva, longe albo-piiosa, Spica solitaria, 2 — 4 

 uncias longa, subcurvata, rachis angulato-niarginata, scabra. Spicularum glomeruli inferiores breviter pedi- 

 cellati, superiores omnino sessiles. Involucrum violaceum, ovato-conicum, dorso convexum, introrsum ad 

 basin bifidum, ibique vulgo lacinia subbifida parva clausum, undique pra>sertim autem basin versus aculeis 

 planiusculis acutissimis ti-iangulariter elongatis erectiusculis creberrime armatuni, apice irrregulariter et le- 

 viter sinuato 3 — 5-fidura, intus et ore pubescens, ceterum glabriusculuni. Glunia exteriör ovata, acutis.sima, 

 flosculos agquaus, hyalina, nervis 3 viridibus notata; gluma interiör exteriori aquilonga, acuta, uninervia. 

 Flosculus sterilis neuter unipaleaceu.s, vel masculus bipaleaceus, paleis hyalinis, filamentis antheris duplo 

 longioribus. Flosculus herma^phroditu.s : palea exteriör dorso subconvexo 3-nervia, basi costis 2 minutis no- 

 tata, apice viridulo subcuspidata, niarginibus interiorem binerviam hyalinani amplectens, lactea. Lodiculse 

 nuUse vel obsoletae. 



Generis Cenchri species raaxime variabjles nondum rite extricata; sunt et cognitse. C. eciiinatus 

 oranium maxime polymorplius et per terras tropicas et subtropicas latissime di.spersus a nostra specie quo- 

 dammodo differt laciniis involucris vulgo basi plus minus concretis et spinulis infequalibus passim obsitis. 

 Non autem est negandum formam in insulis Galapagensibus lectam arctissirao vinculo C. echinato esse 

 affinera. 



* C. GRANULARIS Ands.: culmo erecto, foliis scabris, vaginis pilosis; involucro apice 

 subintegro, introrsum ad basin fisso, dorso tuberculato costato vel laeviusculo, spiculas 

 includente. — Ands. 1. c. p. 140. 



Hab. locis graminosis declivibus reg. inferioris ins. Chatham (Ipse). 



Culmi csespitosi, simplices, a basi erecti v. subexcurvati, pedales, angulati, scabriusculi; nodi augusti 

 infuscati. Folia erecta, medio latiora (2 lin.), superne scabra piiisque raris parce conspersa; vaginaä sub- 

 dilatatse, ad basin fissse, plerumque apertffi, valide striatae, lateribus dense et longe liirsutas; ligula brevis- 

 •sima longe pilosa. Spica fusco-brunnea, valde tenuis, strictissima; rachis rigida, costato-angulata, scabra, 

 Spicularum glomeruli omnino sessiles, niinuti, subgranuliformes. Involucra plerumque difFormia, se. in parte 

 spicse inferiore subechinata, in superiore sublsevia, e basi lata et complanata conica, ore irregulariter si- 

 nuata, apertura introrsa lacinia simplici seepe clausa, omnino glabra; aculei, si adsint, plani, breves, acuti, 

 interdum obveniunt tuberculi rari vel costse plus minus elevatffi, pars superior autem semper nuda videtur. 

 Spiculse inträ involucrum srepissime 2 — 3. ut in specie prsecedente omnino constructse. 



Hebc forma habitu quidem singulari subspecies prsecedentis forsitan est habenda; formas tamen vere 

 transitarias non in insulis vidimus. 



