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XCVIII. E. globulus Labill.

Synonyms.

  • 1. E. globulus Labill., var. St. Johni, R. T. Baker, Journ. Aust. Assoc. Adv. Science, xiv (January, 1913). Also E. St. Johni, R. T. Baker.
  • 2. Vict. Nat., xxx, 127 (November, 1913).

As regards the first reference, Mr. Baker says: “Or sp. nov. … Tentatively placed as a variety.” The description, however, is not sufficient for a new species, nor indeed has the brief Latin description been given, as required by botanical law. Then we have “On a new variety of Eucalyptus globulus—E. globulus, var. St. Johni.,” by R. T. Baker, in Vict. Nat., xxx, 127 (November, 1913).

Following is the paper:—

The Blue Gum, Eucalyptus globulus Labill., has such an extensive range from Southern Tasmania through Victoria to the north of New South Wales, and preserves such a constancy of general morphological characters, that a departure from the normal is of systematic interest; and the honour is due to a Victorian for unearthing this variety. It was discovered by Mr. P. R. H. St. John, on the banks of the Lerderberg River, Bacchus Marsh district, 5th November, 1903, so that at present its location is restricted; but this appears to be the general rule when new species or varieties are discovered. At least a hundred similar trees are growing in the neighbourhood, and there is little doubt but that it will be found to be more widely distributed later on.note

The other species of Eucalypts growing within a square mile of this particular tree are as follows:—E. amygdalina, E. Behriana, E. elœophora, E. leucoxylon, E. melliodora, E. macrorrhyncha, E. hemiphloia, E. polyanthemos, E. sideroxylon, E. viminalis.

The material collected by Mr. St. John is quite complete, consisting of (a) seedling; (b) adventitious shoots, obtained from branch of tree 8 feet from the ground, the tree about 20 years old; (c) leaves from a young tree 6 feet high; (d) leaves from young tree 12 feet high; (e) twig from mature tree, with early buds, mature buds and flowers; (f) twig with fruits from mature tree. The young seedlings have ovatelanceolar, acuminate, petiolate leaves, glaucous above, under surface purplish; the cotyledons or seed-lobes are on slender stalks, and deeply bi-lobed.

(a) The older seedling leaves are oval, sessile, or shortly petiolate, and slightly or not at all cordate; shortly acuminate; not large, about 1½ inches to 2 inches long, and ¾ inch to 1¼ inch or more wide; pale and glaucous on the under side, oil-dots numerous, stem terete, branchlets square.

(b) Similar in shape to those of (a), only longer.

(c) The leaves of the adventitious shoots are longer, orbicular, cordate, lateral veins slightly oblique, parallel, and looping some distance from the edge; branchlets rectangular.

(d) These are large, petiolate, oval, to oval-lanceolate, showing intermediate stage to normal leaves.

(e) This is an interesting specimen, as it shows the inflorescence in every stage. The early stages are characterised by a calyptra, covering two or three buds. The mature buds are more like those of E. Maideni than E. globulus, and differ from the latter in the absence of a second operculum. The calyx is compressed, sessile, about ¼ inch long, ¼ inch and less in width, operculum acuminate, depressed, tuberculate, stamens inflexed before expansion; anthers parallel, opening by longitudinal slits.




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Normal leaves lanceolate, falcate, as in the type, with similar venation, 2 inches to 2 feet or more in length, ½ inch to 3 inches broad, on petioles varying from 1 inch to 2 inches long; oil-dots conspicuous.

The fruits of this variety differ considerably in size and other features from the type; they measure about ¼ inch long to ½ inch in diameter.

The edges of the compressed calyx are here seen to have developed into slightly broken ridges; there is quite an absence of the tubercles so pronounced a feature on the type; the rim is sharp and well defined, and slopes down or upwards to the summit of the valves, that vary in number from two to four.

It is the seedling leaves, the presence of a calyptra in the early buds, the absence of double opercula and the fruits which justify, in my opinion, the tree being given varietal rank.

Then follows a plate of fruits of E. globulus and of the variety, but, unfortunately, they are reduced in size, and, therefore, not easy to interpret. However, in 1920, in the work about to be referred to, Mr. Baker speaks of E. St. Johni as if he had described it.

The references to the species in “Research on the Eucalypts” (Baker and Smith, 2nd ed., 1920) are trivial, and are as follows:—

Page 165 (under E. globulus). “A small, smooth-fruited form that has a wide distribution, and seed distributed abroad, is not E. globulus, but E. St. Johni R.T.B.”

Page 287 (under E. coccifera). “The sessile fruits are near perhaps to those of E. St. Johni, except that this rim is nearly flat.”

Surely this is not the way to describe a species at the close of the second decade of the twentieth century.

Affinities.

1. With E. globulus Labill.

From type specimens placed at my disposal, the fruits of E. St. Johni (and the reputed differences from E. globulus turn on the fruits), are figured at fig. 10, Plate 79, Part XVIII, of the present work. The buds are roughened or tubercled. The points made are that the fruits are sessile, small, and smooth. Neither is a constant character as distinct from E. globulus. See the above plate. Most fruits of E. globulus are sessile. As to size, the fruits vary from even smaller than described by Mr. Baker as for E. St. Johni, to the very large fruits of E. globulus found in Tasmania. As regards smoothness, examination of Plate 79 will show that the character is not rare in E. globulus. See figs. 9a, b, c, and it will be observed that we may have roughness and smoothness, with a considerable amount of variation in size, in the same restricted area of trees. In my view, it is not a species, as distinct from E. globulus, and from what I have just said, its acceptance as a variety would be likely to cause confusion.

2. With E. Maideni F.v.M.

For this species, see Plate 80 of Part XVIII. As regards size and smoothness of the particular fruit chosen as typical of E. St. Johni, these characters are common enough in E. Maideni, which may be both sessile and pedicellate. But whether E. St. Johni can stand as a species can best be discussed under E. globulus.

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