36 THE VOYAGE OF H.M.S. CHALLENGER. 



RUBIACE^. 



Eedyotis adscensionis, DC. (Plate XVI.) 

 Hedyotis adscensionis, DC., Prodr., iv. p. 419. 



Skerardia fruticosa, Linn., Sp. PL, ed. i. p. 103, et ed. 2, p. 149; Forst. in Comment. Goett., ix. 

 (1767) reprint, p. 40. 



Ascension. — Endemic. Osbeck ; Lesson ; Hooker ; Seemann ; Moseley. 



Osbeck collected the plant which Linnaeus described under the name of Sherardia 

 fruticosa, and there is no doubt that De Candolle's Hedyotis adscensionis is the same 

 species, though there are great discrepancies in the description. Linnaeus had a stunted 

 specimen, like that represented in our figure B, in which the flowers are solitary and 

 almost sessile. De Candolle had a specimen in which the peduncles were one-flowered 

 and shorter than the flowers. In more robust specimens, collected by Seemann, the 

 peduncles are often two-flowered, and the peduncle and pedicel together are twice or 

 nearly three times as long as the flowers. The plant is not only very variable in the 

 degree of scabridity, in the size of the leaves, length of the peduncle, and in the sizes of 

 the flowers, but the latter are also dimorphic, differing in the relative lengths of the calyx 

 lobes and the corolla tube, and also apparently in the position of the stamens. Whether 

 these dimorphic flowers are functionally unisexual the accessible material is insufficient to 

 determine, for the specimens are mostly quite past the flowering stage, and the others 

 bear very few flowers, all of which are expanded and old. Both the long and short 

 flowers have, however, exserted styles of about equal length. 



EUPHORBIACE^E. 



Euphorbia origanoides, Linn. (Plate XVII.) 



Euplwrbia oriijanuidcs, Linn., Amcen. Acad., iii. p. 114, et Sp. PL, ed. 1, p. 453 ; Forst. in Comment. 

 Goett., ix. (1787), reprint, p. 46; Buissier in DC. Prodr., xv. pars 2, p. 15. 



Ascension. — Endemic. Osbeck; Hooker; Seemann; Curror ; Moseley; and in the 

 British Museum collected by Buchanan. 



MONOCOTYLEDONES. 

 CYPERACE^. 



Cyperus umbellatus, Benth. 



Oyperus umbellatus, Benth., Fl. Hongk., p. 386, et Fl. Austr., vii. p. 289. 



Cyperus raj, if,,, Steud., Glumif. Cyp., p. 28. 



Mariscm umbeUatus, Vahl, Enum., ii. p. 376; Kunth, Enum. PL, ii. p. 118. 



Mariscvs appi ndiculatns, Brongn. in 1 >uperr. Voy. " Coquille," Lot. Phanerog., p. 178, t. 34 A. ; Kunth, 



Enum. PL, ii. p. 81. 

 Mariscue polyceplialus, .\. Rich., Serturn Astrolab., Lot, p. Iii. 1 



Ascension.— Indigenous? Lesson; Durville; Hooker. 



