On Three Species of Delesseriaceæ from New Zealand.
[Communicated by Mr R. M. Laing. Read before the Philosophical Institute of Canterbury, 4th November, 1931; received by Editor, 5th November, 1931; issued separately, 28th February, 1933.]
Some years ago I obtained from Mr R. M. Laing a collection of New Zealand species of Delesseriaceae in order to verify the determination of the different species. My determinations are published in a previous paper (1929). Since then I have got some more species of Delesseriaceae, and in consequence thereof I have some more remarks to make about three New Zealand species of this family.
Erythroglossum undulatissimum (J. Ag.) Kylin nov. comb.
Nitophyllum undulatissimum J. Ag. (1898) Sp. Alg. III: 3 p. 59; Myriogramme undulatissima Kylin Deless. p. 60, Kylin Deless. Neu Seeland, p. 9, taf. 6, fig. 14.
This species was for the first time collected in New Zealand by F. von Müller in 1885 and described by J. Agardh in 1898, who, with a question mark, referred it to the genus Nitophyllum. Later on Kylin referred it to the genus Myriogramme, described by himself in 1924.
Photographs of the species in question are published by Kylin (1929, taf. 6, fig. 14). The type-specimens are not good, and therefore it is difficult to make sure of the genus to which this species is to be referred. In the above mentioned collection of Laing there was, however, a specimen because of which I doubted the correctness of referring the species in question to Myriogramme (Kylin 1929, p. 9).
Now I have some dried specimens of Nitophyllum undulatissimum J. Ag. as well as some ones preserved in alcohol. They are sent by Laing, who found them cast ashore in Lyttelton Harbour, New Zealand, on the 13th July, 1930. The material preserved in alcohol has made it possible to study the growing points. In the growing point there is always a special apical cell which downwardly by transversal walls is cutting off segment-cells. Immediately below the growing point there occurs a lot of intercalary cell-divisions.
In each lobe of the frond there is a macroscopic main-rib; neither side-nerves nor microscopic nerves are to be found. It is, however, possible that the main-rib in a side-lobe resembles a side-nerve, but there is no connection between a side-nerve of this kind and the midrib in the main-lobe. All branching of the frond starts from the frond-margin.
The above mentioned vegetative characters prove that Nitophyllum undulatissimum is to be referred to the genus Erythroglossum, and not to the genus Myriogramme, as in the latter genus a special apical cell is never to be found in the growing point of the frond.
The development of the procarps in Erythroglossum undulatissimum takes place in the same way as in the genus Myriogramme (Kylin 1924, p. 56). The cystocarps are scattered over the surface of the frond. In the gonimoblast-filaments are many carpospores ranging one after the other. The tetrasporangia occur in a single row of roundish or elliptical sori, 0, 5 mm. in diameter, between the main-rib and the margin of the frond, generally somewhat nearer the margin.
Erythroglossum Laingh Kylin nov. spec.
Frond 8–10 cm. high, light red, flat, membranous, much laciniate; the main-laciniae 4–6 mm. broad, with a macroscopic midrib, but without side-nerves or microscopic nerves; the ultimate laciniae 4–8 mm. long and 1 mm. broad, with a mid-rib, but without side-nerves or microscopic nerves; all branching of the frond starts from the frond-margin; growing point with a special apical cell, immediately below the growing point there occurs a lot of intercalary cell-divisions in the same way as in Erythroglossum undulatissimum; cystocarps and tetraspores unknown. Specimens from New Zealand, Lyttelton, Governor's Bay; drift 28th July, 1929; R. M. Laing.
Abroteia suborbicularis Harv.
Abroteia suborbicularis Harv. (1855) Fl. Nov. Zel. 2 p. 242; Nitophyllum ? suborbiculare Harv. l. c.; Abroteia orbicularis J. Ag. Epicr. p. 694; Myriogramme oviformis Kylin Deless. Neu Seel. p. 9, taf. 6, fig. 13.
In my paper about the New Zealand Delesseriaceae I described a new Myriogramme species under the name of M. oviformis. Later I found, however, that this species was earlier described by Harvey under the name of Abroteia (Nitophyllum ?) suborbicularis. The genus Abroteia seems to be nearly related to Myriogramme.
Agardh, J. Epicrisis Systematis Floridearum. Lund, 1876.
—– Species, Genera et Ordines Algarum, vol. 3, pars 3. Lund, 1898.
Hooker, J. D. The Botany of the Antarctic Voyage II. Flora Novae Zelandiae. London, 1853–1855.
Kylin, H. Studien über die Delesseriaceen. Lunds Univ. Arsskr., N. F. Avd. 2, Bd. 20. Lund, 1924.
—– Die Delesseriaceen Neu Seelands. Lunds Univ. Arsskr., N. F. Avd. 2, Bd. 25. Lund, 1929.