From George Bentham   22 December 1862

Decr 22/62

My dear Sir,

Since I last wrote, with the exception of nearly a week's interruption owing to indisposition which I have now quite got over, I have been steadily at work at Rutaceae. Dr Hooker did them for the Genera¹ when he could not of course examine every species, but now a detailed analysis of every species and variety and often of many specimens induces me to keep up most of the established genera as he proposes. I have done Zieria Boronia Eriostemon Crowea and Phebalium all of which appear to me to be natural as well as definitely characterised and too generally kept up by botanists of eminence to be lightly interfered with — whatever we might have done if we were beginning de novo with all our materials without any one having gone before us. Boronia took me a great deal of time. Drummond's collections are very rich in them and his specimens being usually full sized (in those herbaria where they have not been broken up) and having several sets from different herbaria before me they have afforded me very satisfactory materials in connection with yours and others. I only wish Preiss's had been better. In Brown's and Cunninghams I have three new tropical Boronias and altogether I make up 56 species. You will no doubt think I have too many, and you may be right, but where races are distinctly characterised so far as our materials go and there is a doubt whether they are species or varieties I think it better (ad interim) to describe them as species where they are generally considered as such, or as varieties where they are so published unless I am convinced to the contrary — and where I keep separate what you have united I take care to state your opinion that you may have full credit if further evidence confirms it — as I have little doubt it may in several instances. I find with you that Cyanothamnus merges into Boronia — which is not divisible into sections of quasi-generic value although the estivation of the corolla & inflorescence make very good artificial sections. In Zieria which I keep up as a genus the estivation of the corolla sometimes all but valvate at others much imbricate is scarcely even of specific value. In Boronia strictly valvate in 16 species much imbricate in all the others it establishes two well-defined but very artificial groups the terminal and axillary inflorescence is also generally speaking a constant specific character and with a little care can be traced in most species where it is at first sight ambiguous. B. nematophylla and B. crenulata are perhaps the only ones where besides the terminal cluster there are also axillary flowers down the branches. — In Eriostemon (of which the overrating of species in the Genera was owing to a mistake) the petals are always much imbricate. — In Phebalium (your sections Leionema and Phebalium) besides the differences in aspect and stamens, the petals are either strictly valvate as in Leionema or if imbricate as in Phebalium proper the tips are valvate with the inflected points as in the others. — In Crowea I think I must keep up your C. exalata — the flowers are never terminal in C. saligna & angustifolia always terminal in C. exalata or if sometimes apparently axillary we always find a leaf or two at the base of the pedicel showing that the flower terminates a reduced branch whilst in C. saligna & angustifolia there is never the slightest trace of a leaf at the base of the pedicel. With regard to the smaller genera adopted by Dr Hooker Urocarpus had better be regarded as a section of Asterolasia, thus forming a genus distinguished as well by the almost obsolete calyx and induplicate-valvate corolla as by the ovary and stigma. I have little doubt also that Drummondita may merge into Philotheca but the union would be premature without more complete specimens, and Microcybe with 3 spp & Geleznowia with 3 appear to me both sufficiently distinct to stand.

You will now I suppose soon be at Leguminosae for Fl. Vict. — you will see that since the paper I published at Vienna 25 years ago² there are many modifications. I do not think that Callistachys can stand as a genus distinct from Oxylobium — Gastrolobium runs into Oxylobium but must be kept up if possible — but I have not worked much lately at specially Australian genera — some of my Kennedioid genera cannot stand — Leptocyamus merges into true Glycine which includes Shuteria, Johnia and Soja and contains one Glycine of the older Linnaeus — Glycine as limited by Wight and Arnott³ contains no true species of the older Linn. only one of his son — and is Teramnus Sweet. — This & many other tropical genera are characterised with as much care as I could in the Papilionaceae of Martius' great Flora Brasiliensis.⁴ — The genera made out of Bauhinia which I had adopted in Pl. Junghuhnianae⁵ must be I think reduced to sections — and so some of the other little Desmodioid genera — Is Swainsona really distinct from Astragalus (Phaca)? I shall be anxious to see the result of your working up the Australian members of that fine Order.

I forget whether it was before or since my last that the plants pr Gt Britain arrived safe at Kew so that I have now all that you sent. When I have done Rutaceae I will send you back a 2d & perhaps a 3d box.

Decr 29 I have kept this open till now in case any letter should come from you but owing to the wreck of the Colombo most of the Australian letters are delayed and some it appears are lost.⁶

Ever yours sincerely

George Bentham

Dr F. Mueller.

Asterolasia

Astragalus

Bauhinia

Boronia crenulata

Boronia nematophylla

Boronia viminea

Callistachys

Crowea angustifolia

Crowea exalata

Crowea saligna

Cyanothamnus

Drummondita

Eriostemon

Gastrolobium

Geleznowia

Glycine

Johnia

Leguminosae

Leionema

Leptocyamus

Microcybe

Oxylobium

Papilionaceae

Phebalium

Phebalium sect. Leionema

Phebalium sect. Phebalium

Philotheca

Rutaceae

Shuteria

Soja

Swainsona

Teramnus

Urocarpus

Zieria