302 OBSERVATIONS ON PLANTS 



this calcar is equally manifest in the terminal rudiment of 

 tlie locusta. The present, therefore, is a case of more re- 

 markably oblique articulation in grasses than even that 

 245] existing in Ilolcus acicidaris (Andropogon acicularis, 

 Betz), which led to the formation of CenirojjJiorum, a genus 

 still admitted by Professor Sprengel,^ and respecting the 

 structure of which a very singular explanation has been 

 lately offered by M. Raspail.^ In one respect, the two 

 cases differ. In Banthonia [Centrojjodia) Forshalii, the 

 articulations being in the axis of the locusta or spicula, each 

 flower appears to have this spur-like process ; while in 

 Holcas CRhapJds) acicularis, the joint being in the peduncle 

 or branch of the racemus, the spur is common to three 

 locustae. 



Dr. Fischer, in whose herbarium the specimen was ob- 

 served which led to the formation of Centrophorum, will 

 probably recollect the communication made to him on 

 the subject of that plant, of which Dr. Trinius himself 

 has since corrected the characters. He retains it, how- 

 ever, as a distinct genus, for v\diich he has adopted 

 the name Rhaphis, given to it by Loureiro, by whom it 

 Avas originally proposed on other; but not more satisfactory 

 grounds. 



Triraphis Pumilio is the second plant of this family to 

 be noticed. It is undescribed, and belongs to a genus of 

 which the only two published species Avere found in the 

 intratropical part of New Holland.^ In several points of 

 structure the African plant is very different from T.^jun^ens, 

 the first of these species ; in some respects it approaches to 

 mollis, the second species, especially in the inequality of its 

 setae or aristcC ; but it differs from both in habit, and in 

 having only one perfect flower in each locusta.* 



Of Pennisetum dichotomum {Delile, Flore cVUf/yjjfe, p. 

 15, tab. 8,/. 1), which, in several different states, is in 

 the collection, it is remarked by Dr. Oudney that " it 



1 Si/st. Veg. 1,;;. 132. 2 Annul, des Scien. Kat. 4, p. 425. 



3 Proclr. Flo,\ Nov. Boll 1, ;;. 185. ^ 



^ Triraphis Pumilio, panicula coavctata abbreviata, locusta glumam vix supe- 

 raiite 3-1-liora : flosculo infimo licrraaplirodito ; rcliquis neutris uuivalvibus. 



