40 THE VOYAGE OF ELKS. CHALLENGER. 



dendron. From Bertero's specific name, thurifera, this tree is doubtless one of those that 

 yield incense, though he quotes no native name for it on his label, merely recording its 

 height as eight to ten feet. Most likely, however, it is the tree referred to by him (Ann. 

 Sc. Nat., xxi. p. 347) in the following sentence :— "Un arbre assez eleve, et de la tribu 

 des Eupatorinees, me parait tout-a-fait inconnu ; il donne une gomrae resine qui a aussi 

 la meme odeur que l'encens." The "Eesina macho" and the " Resina hembra" mentioned 

 are species of Robinsonia. No record is to be found of the relative frequency of Rhetino- 

 dendron ; but as it is in the later collections, it is probably not uncommon. Bertero's 

 specimens in the Kew Herbarium include a seedling plant, about fifteen inches high, 

 the leaves of which are shorter, broader, and very coarsely toothed. 



Robinsonia evenia, Philippi. 



Robinsonia evenia, Philippi in Bot. Zeit., 1856, p. 644. 



Juan Fernandez. — Endemic. Reed; Moseley ; Downton. 



Philippi describes this as a shrub about six feet high. In many of its characters it 

 agrees with Decaisne's Robinsonia macroc&phala, while in others it is apparently very 

 different. Probably some of these differences are only sexual, and there may be no more 

 than three or four distinct species of Robinsonia in the island. The flower-heads are 

 always (?) in all the species (?) unisexual, and, as far as examined, all the flower-heads of 

 a specimen are either male or female ; hence it may be assumed that the sexes are borne 

 by different plants. In consequence of this separation of the sexes, it is impossible to limit 

 the species without ample materials, for we cannot tell what other differences the sexes 

 may present. In De Candolle's Prodromus, the bristles of the pappus of Robinsonia are 

 described as cohering in a tube nearly half-way up — -a condition not found in any of the 

 specimens we have examined. Robinsonia evenia differs essentially from the other species 

 in the involucral bracts being free to the base, and it has all the aspect of a true Senecio. 

 It may be mentioned that De Candolle named this genus, which is endemic in Juan 

 Fernandez, after Defoe's hero. 



Robinsonia gayana, Dene. 



Robinsonia yaijana, Dene in Ann. Sc. Nat., ser. 2, i. p. 2S, t. 1 ; Delessert, le. Set, iv. t. 64 ; DC, 



Prodr., vi. p. 448; Gay, El. Chil., iv. p. 126. 

 Robinsonia corrugata, Philippi in Lot. Zeit., 185G, p. 645. 

 Senecin thurifer, var. ! Bertero MSS. in Herb, Kew. 



Juan Fernandez. — Endemic. Thickets in stony places of the higher mountains — 

 Bertero; Douglas; Reed; Moseley. 



This species and Robinsonia thurifera, Dene., are not readily distinguishable. Bertero 

 regarded them broadly as one species, yet he points out differences, and suggests that there 



