Art. XXXIX.—Remarks on Gunnera “ovata,” Petrie, and G. flavida, Colenso, in Reply to Mr. Petrie.
[Read before the Wellington Philosophical Society, 16th February, 1898.]
In the last volume of the “Transactions of the New Zealand Institute”* Mr. Petrie takes exception to my pointing out his error in confusing two distinct plants under the name of “Gunnera ovata,” combining the flowers of one with the fruit of the other. As a careful re-examination of the facts of the case has fully confirmed this conclusion, I have to offer a few observations in support of it.
The only fact advanced by Mr. Petrie in support of his contention is that the fruit of Colenso's G. flavida has fleshy drupes, while G. “ovata” has drupes “which are hard and almost stony, with no fleshy exocarp or covering of any kind.”
The putamen of the drupes of almost any Gunnera is “hard and almost stony,” and if picked in December or January will certainly be destitute of a “fleshy exocarp.” If it be gathered during March or April the fruit of G. “ovata” will probably, but not invariably, have a pulpy or juicy sarcocarp. This is the simple explanation of the error into which Mr. Petrie has fallen.
No New Zealand species of Gunnera has the fruits invariably fleshy. I have before me Southland specimens of G. flavida, collected in January, which are quite hard, and specimens from the same locality, collected in April, which show the thin epicarp loose on the putamen, owing to the absorption of the pulpy juice. The earlier specimens are almost as deeply coloured as those fully mature.
From this it will be evident that I cannot accept Mr. Petrie's dictum that fleshy drupes constitute a “most important differential character.” It is at best but a secondary character of comparatively little importance. Mr. Petrie will remember at one time having been inclined to attach a similar
[Footnote] * Trans. N.Z. Inst., xxix., p. 422, art. xxxvi.
degree of importance to the absence of the juicy sarcocarp in certain specimens of Nertera setulosa which he was good enough to send me. In some species of Podocarpus and Dacrydium pulpy fruits are extremely rare in many seasons; so also in small-flowered varieties of Pratia angulata and other plants.
But Mr. Petrie has further confused the subject by raising the question of the distinctness of G. prorepens, Hook. f., and G. flavida, Col., but without offering the slightest argument in evidence beyond the statement that he “entertains no doubt as to their identity, and that the same opinion is held by the authorities at Kew.” Now, I should be sorry to seem to cast doubt on the value of conclusions adopted by members of the staff of that institution, even although I might not be able to agree with them; but in the present case Mr. Petrie must be under some misapprehension. I did not forward specimens of Gunnera to Kew until after my revision of the New Zealand species of Gunnera had been printed, so had not the advantage of their being compared with other forms. Somewhat earlier, however, at the request of the Director, I forwarded seeds of several species, and received a memorandum written by Mr. Hemsley stating that he considered G. flavida, Col., identical with G. prorepens, Hook. f. When next communicating with Kew I pointed out the impossibility of maintaining this opinion, and received through the Director a memorandum written by Mr. N. E. Brown, who stated that the two plants had always been considered distinct at Kew, and that Mr. Hemsley had no recollection of having expressed an opinion to the contrary, while he was unable to find any specimen of G. flavida with the name of G. prorepens attached. It is evident, therefore, that this opinion is not entertained at Kew at the present time.
Mr. Petrie states that the drupes of G. prorepens are fleshy, but I have never found them so, and they are not so described by Hooker. His assertion that Mr. N. E. Brown's opinion respecting the undetermined Gunnera mentioned in the Handbook has been ascribed to him by me is equally misleading. His opinion is expressly stated to be “on the authority of Mr. N. E. Brown” (p. 346, Trans. N.Z. Inst., vol. xxvii.). Other similar assertions might be mentioned, and for one at least there is absolutely no excuse. Mr. Petrie states, “Mr. Kirk no doubt means to say that a number of specimens sent him by me under the name of G. ovata contained, in his opinion, two distinct plants, which is a very different thing, and may or may not be the fact.” This should not have been written, since on receipt of his specimens—two in flower and four in immature fruit—I at once informed him by letter that he had two distinct plants.