It will be perceived that my description of this plant differs _materially_ from that of _Mr. Nuttall_. This has unavoidably arisen from _my_ having attended to it in its living state, and from _his_ not availing himself of the information which it would have afforded me pleasure to have communicated, had he done me the favour to have requested it, or informed me of his wish to publish an account of plants thus obtained. He has called the culm _solid_, leaves _rather short_, spikes _cylindric_, _axillary_, the flowers and rachis _entirely smooth_, pedicel of the neutral flower _emarginate_, outer valve of the hermaphrodite calyx _acute_, the valves of the corolla _obtuse_, and the styles _very short_. I have not been able to confirm the above _characters_, nor do I find them even in the dried specimens. Besides, he has omitted to inform us that the rachis is _naked on one side_. This is a most important and prominent _specific character_, the omission of which would necessarily lead to much doubt in identifying the species. What he means by stating that the "outer valve of the hermaphrodite flower is 3-valved," I cannot imagine, nor do I comprehend what is intended by an "exterior auxiliary valve, or neutral rudiment; nearly the length of the calyx." I have noticed in a single instance, connected _laterally_ with the corolla of the perfect flower, two very delicate, narrow, acute pointed bodies, the length of the outer valve, and of the same quality and appearance; but these I have considered as accidental, and cannot perceive any thing about them like _neutral rudiments_. Nor can I consider the articulations of the rachis as "deeply excavated." They are, as already stated, flat on the inner side, and constitute from their _flexuous_ form, position, and connexion with the pedicels of the neutral florets, an arch, in which the perfect flowers are situated. _Rottböllia ciliata._[52] Culmo erecto, tereti, glabro, ramoso: foliis angustissimis, brevibus: spicis cylindricis super pedunculis teretibus longis, solitariis terminalibusquæ: calycis bivalvis, margine valva exteriori _ciliata_: corolla bivalvis. Culm erect, terete, smooth, ramose: leaves very narrow, short: spikes cylindrical upon long terete peduncles, solitary and terminal, calyx 2-valved, the margin of the exterior valve _ciliate_: corolla 2-valved.