To George Bentham   24 November 1863

Melbourne bot Garden

24/11/63.

Dear Mr Bentham.

Since I last wrote to you, I have worked a little on Eucalyptus and have placed all the specimina of this intricate genus into preliminary order for your use. In doing this I had not sufficient leisure to examine carefully all the specimina accumulated since I elaborated the species for the second volume of the fragmenta.¹ Those used for my former writings are glued on the paper-sheets, the others not.

I see but few additional species and believe, that when once the cyclus of forms of each species is ascertained we shall not muster more than 100 distinct ones. My material will be of great use to you, to show how variable the character is, derived from the operculum &c, and you will find of most species a fair set of specimina, indeed the whole amounting to about 60 large fascicles. Of most kinds you will find duplicates for retention at Kew. Leichhardts Eucalypti comprise 4 fascicles & there is moreover a small set of Siebers, which you will be so good to return to Dr Sonder, who obliged me with the loan of these.

I have ascertained beyond doubt, that Eudesmia tetragona & Eucalyptus pleurocarpa are identical as to species and I cannot alter my opinion that Eudesmia is nothing but a subgenus of Eucalyptus, the fasciculation of the stamina not being always very distinct and oweing to the angular formation of the capsules.²

Callistemon I have also examined. It is a perplexing genus and I cannot see how the species are to be circumscribed unless under large reductions. The Synonymy is not readily revealed. The figure of Callistemon speciosus in Bot. Mag.³ leaves it doubtful, whether it applies to C. glaucus of West Australia or to some East Australian species. DC says it is East Australian. You however will have full means of settling the point on inspection of dried garden specimens. My collection comprises 6 fascicles of Callistemon, a fair set.

Altho' generic distinctions are never absolute and thus Callistemon might be kept up, I propose to bring it back to Melaleuca. The stamens of C. lanceolatus are sometimes concrete at the base, and the ring thus formed readily breaks into 5 phalanges. On the other hand Melaleuca Leucadendron produces sometimes forms in which the stamens are all but free, and this misled Prof Lindley to describe a variety of it as Callistemon nervosus. You will probably in consideration of the lenght and color of the [stamens] & differences in leaves be inclined to distinguish several Melaleucae in what I have condensed as Melaleuca Leucadendron. Nevertheless I have vainly endeavoured to discriminate the varietys as species, when for many months in North Australia I saw almost daily this plant. On the Sandstone tablelands, where it is equally common as on the river banks it assumes a very different appearance, but a field botanist would fail to discriminate between these forms, which flow perfectly together. RBr (vide Flinders) however did not adopt this view.⁴ Metrosideros glauca of Bonpland (My Callistemon glaucus)⁵ was raised at Malmaison from seeds gathered [on] Baudins Expedition, so the plant came probably from West Australia. The figure furnished by Bonpland⁶ is however uninstructive and devoid of the veins, which are prominent or at least conspicuous in the leaves of my West Australian plant. It cannot, I think, represent a state of Callist. rigidus. What is Call. scaber Loddiges? As far as I know, no copy of Loddiges Cabinet⁷ is in Victoria.

I have recently received Bonnaya veronicifolia from Queensland a plant, seemingly not before gathered in Australia.⁸

Bonnaya veronicifolia

Callistemon glaucus

Callistemon lanceolatus

Callistemon nervosus

Callistemon rigidus

Callistemon scaber

Callistemon speciosus

Eucalyptus pleurocarpa

Eudesmia tetragona

Melaleuca Leucadendron

Metrosideros glauca