Journal of the Department of Agriculture, Western Australia, Series 4

Volume 3 Number 5 1962 Article 11

1-1-1962

Trees of Western Australia. No. 97. The River gum (Eucalyptus camaldulensis Dehn.). No. 98. Jutson's mallee (Eucalyptus Jutsonii Maiden)

Charles Austin Gardner

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Recommended Citation Gardner, Charles Austin (1962) "Trees of Western Australia. No. 97. The River gum (Eucalyptus camaldulensis Dehn.). No. 98. Jutson's mallee (Eucalyptus Jutsonii Maiden)," Journal of the Department of Agriculture, Western Australia, Series 4: Vol. 3 : No. 5 , Article 11. Available at: https://researchlibrary.agric.wa.gov.au/journal_agriculture4/vol3/iss5/11

This article is brought to you for free and open access by Research Library. It has been accepted for inclusion in Journal of the Department of Agriculture, Western Australia, Series 4 by an authorized administrator of Research Library. For more information, please contact [email protected]. RIVER GUM (Eucalyptus camaidulensis Dehn.) A Branchlet with leaves and flower-buds; B—Flower-bud (enlarged); C—Anthers (enlarged): D. and F- Fruits (E and F enlarged); O—Fruit in longitudinal section. Bowes River, Gardner 13166 378 Journal of Agriculture Vol 3 No 5, 1962 TREES

No. 97—THE RIVER GUM There is remarkable variation in the shape and comparative length of the (Eucalyptus camaldulensis Dehn.) flower-buds, the operculum or bud-cap varying from almost egg-shaped (as in the accompanying plate) to conical and HIS tree, which has a wide range with­ beaked. The latter forms are found mainly T in the continent was for many years in eastern Australia and in the southern known as Eucalyptus rostrata, the Murray areas of its distribution in Western Aus­ River Red Gum. tralia. A number of varietal names have been given to the various forms, but in Its range of distribution extends from Western Australia we can recognise within Queensland and the Northern Territory to the summer rainfall area only two, the one the drier parts of Western Australia, South illustrated, and a form common in K:m- Australia, New South Wales and Victoria. berley in which the operculum is somewhat In Western Australia it is confined more shorter and broader and terminates in a or less to the banks of watercourses within small short abrupt beak. A form much like the summer rainfall zone, which brings it this is also found in the Leonora district. southwards to Wiluna and Meekatharra and the Bowes River not far to the north Southwards from the Bowes River in from Geraldton. the winter rainfall area the tree undergoes a gradual change at first almost imper­ In these areas it is found as a smooth- ceptible. The bark remains smooth and barked gum tree, varying in its appear­ white, but the fruits become somewhat ance from north to south and from west broader and almost hemispherical. This to east. For example, in Victoria and smooth-barked form with the almost South Australia it occurs as a thick- hemispherical domed fruits extends to the stemmed gum tree with widely spreading vicinity of the Moore River, and occasional branches rendered familiar by paintings; trees are found as far to the south as in the north it has quite a different Northam, but in the vicinity of the Moore appearance, being a comparatively slender River we find a rough-barked tree with stemmed tree up to 70 feet tall with a broader leaves, larger and broader flower- trunk up to 35 or even 40 feet high, with buds and fruits with the disc scarcely or comparatively slender erect or spreading not at all domed. The timber is pale. This branches, the bark always white and is the "flooded gum" (Eucalyptus rudis) smooth. which occupies the same environmental The foliage varies in colour from green conditions as the river gum. to a blue-green and the leaves are fre­ Although readily separable in its quently very long and narrow. The timber southern range from the river gum, the is a pale to deep red in colour, and straight- flooded gum cannot be separated from grained. this tree in the region extending from the 379

Journal of Agriculture Vol 3 No 5, 1962 JfUTSON'S MAIXEJE A—Branchlet with leaves and flower-buds; B—Leaf; C—Flower buds of the broader type (enlarged); D—Flower- bud in longitudinal section; E—Anthers; F—Fruits; O—Fruit enlarged; H—Fruit in longitudinal section. Comet Vale, Gardner 13859 380 Journal of Agriculture Vol 3 No 5, 1962 Bowes to the Moore rivers. The difference No. 98-JUTSON'S MALLEE in the two types of bark is considerable, being smooth and white in the north, and (Eucalyptus Jutsonii Maiden.) rough and fibrous-flaky in the south. The difference in timber is not so remarkable HIS species commemorates the name of or important, since we have occasional T J. T. Jutson, a field geologist of the tuart trees in which the timber is light red, Geological Survey of Western Australia and similar differences have been observed from 1911-1918, well known as the author in other trees, although rarely so. Both of "The Physiography of Western Aus­ trees are generally spring and summer tralia." He collected both this species and flowering. E. comitae-vallis at Comet Vale. One of the most interesting features of E. camaldulensis is that although re­ The species is a very distinctive one, stricted almost entirely to the vicinity of growing in red sand at Comet Vale. It streams, it proves hardy under cultivation attains a height of 25 feet, and is a small in a variety of soils and climates. For tree, or more commonly a mallee with close example we see it at Onslow growing on erect leafy branches. The stem is up to the coast in red sand; it has proved equally six inches in diameter, and covered with hardy in the sandplain country of our a light grey flaky and longitudinally fis­ southern agricultural districts, as well as sured persistent bark which becomes in the red clay loam, and one gains the stringy in the upper trunk, the branches impression that it can be grown anywhere and branchlets, and usually the upper part in Western Australia. of the trunk with a smooth silvery-reddish It is remarkably rapid growing, and is brown bark. recommended for planting in the eastern The leaves are remarkably narrow and agricultural areas as well as in the pas­ very finely pointed, and commonly five to toral district; large trees occur naturally six inches long but rarely more than three- as far inland as Leonora and Doyle's Well, eights of an inch broad, a bright lustrous at Wongawal, at Roebourne and the green on both surfaces, and always erect. Strelley River, and at Nannine, while in The flowers are in axillary umbels of Kimberley it is the most common tree of commonly four or five flowers on short the watercourses, especially in sandy soil pedicels, the operculum varying from nar­ on the banks of the intermittent rivers row conical to broadly conical, and longer and their tributaries. than the hypanthium. The white staminal It is not recommended for street plant­ filaments are inflected in the bud, and ing or planting in suburban residential bear small anthers (versatile) which open blocks on account of its size and the brittle in small oblique slits, sometimes confluent nature of the branches, a characteristic at the apex. it shares with the lemon-scented gum The small fruit is hemispherical, about (E. citriodora.) a quarter of an inch in diameter, with a The timber is in common use in the wide slightly domed disc and three broad tropical areas for structural purposes, deltoid valves. The style is relatively thick being very strong and straight-grained, but and slightly dilated in the upper part. it will not withstand the ravages of E. Jutsonii flowers in December. It is termites and should never be placed in most closely related to E. angustissima of contact with the soil. the south coast around Israelite Bay.

381 Journal of Agriculture Vol 3 No 5, 1962