[ 43 ] 



VII. On the Family o/Triuriacege. By John Miers, Esq., F.B.S., F.L.S. fyc 



Read April 2 and 16, 1850. 



IT is now about nine years since I offered to the notice of the Linnean Society the descrip- 

 tion of Triuris hyalina, which was honoured by a place in its Transactions *. Upon that 

 occasion, after giving the details of its structure, I remarked, that as it could not be 

 referred to any known natural order, it might be received as the type of a distinct family, 

 which I suggested as holding a place near Fluviales, or Burmanniacece, but whose positive 

 rank in the system could not be known until we obtained some information relative to the 

 structure of the seed and its embryo f. 



The subsequent discovery, by my much lamented friend Mr. Gardner, of a very analo- 

 gous plant with female flowers only, differing in no respect from Triuris, except in having 

 six divisions instead of three in the perianthium, and in a more lateral and less pointed 

 style, supplied an interesting fact ; but as its carpels were not in a more advanced state of 

 development, it afforded no insight whatever into the structure of the seed. That inde- 

 fatigable botanist, whose recent loss we must all greatly deplore, in the paper he presented 

 to the Society on this subject %, offered several speculations upon the affinities of his plant 

 and of Triuris, tending to show, as I will prove, erroneously, that they were allied to Smi- 

 lacece ; and upon such unestablished data he drew out § a diagnosis of the family I had 

 previously suggested. In that memoir he stated, that in juxtaposition with his plant he 

 found another of similar size, presenting a single petiolar blade, much resembling the leaf 

 of a Cissampelos || . Although he failed in tracing any underground connexion between the 

 roots of these two plants, he concluded too hastily that the one appertained to the other, 

 and hence he inferred that his plant was related to Menispermacece or Smilacece. He 

 offered at the same time an opinion, that I had overlooked a similar distinct leafy append- 

 age in Triuris ; but this certainly was not the case, for on quitting the Organ Mountains 

 in 1838, 1 carefully gathered all the specimens I could find, with the soil and moss attached, 

 keeping them well moistened for two months, until I embarked for England, hoping to 

 witness a further development of the ovaria : at the same time, I examined the moss for 

 any remains of seed or seed-vessel of previous growth : and hence I feel assured that had 

 any such leafy appendage existed in connexion with Triuris, it could not have escaped my 

 frequent and searching observation. The stem of Triuris, in the living state, is quite hya- 

 line and transparent, appearing composed of simple cellular tissue, without any visible 

 longitudinal vessels, except toward the centre, where it is somewhat more compact. On 

 comparing Mr. Gardner's plant with Triuris in the dried state, both exhibit a similar struc- 

 ture, appearing quite translucent externally, with central darker axile lines. The stem of 



