Ferdinand von Mueller

1

Letter not found. The text given here is from ‘The cape weed’, Argus, 23 October 1863, p. 6 ( B63.10.03).

Sir, —

In response to a query made through The Argus of yesterday,

2

M wrote in response to a letter by 'Cui Bono' (Argus, 20 October 1863, p. 6) that raised the problem of the insidious nature of the cape weed. This matter, the writer said, had previously been raised by M when he 'stated in your columns his experience in endeavouring to exterminate this weed, which first made its appearance in the paddock adjoining his house, and as that gentleman is so keenly observant of everything botanical, it may be in his power to furnish us with some information as to its introduction and establishment in that locality'. No earlier report by M has been identified; the reference may be to a more general report in which M's efforts at eradicating the weed from the reserve next to the Botanic Garden are recounted; see Argus, 6 October 1862, p. 6.

I beg to remark that it remains unascertained whether the Cape weed (

Cryptostemma calendulaceum

Search for Cryptostemma calendulaceum in

• This website
• Australian Plant Name Index

), now so frequent around Melbourne, and so rapidly invading many districts of our colony, was directly introduced from South Africa, or came accidentally across from the settlements of South or West Australia. As early as 1847 I noticed it extensively in the environs of Adelaide; and I found it widely established around Melbourne on my arrival, several years later, and not restricted to any special reserve. Baron von Huegel noticed the Cryptostemma as early as 1833, in Western Australia; and Dr. Preiss records it, some years later, from localities widely distant of that colony. But whilst its origin in all these places cannot be traced, it is gratifying to know that this plant has as yet neither reached Tasmania nor the eastern coast of Australia.

Although the extirpation of the Cryptostemma on Victorian soil has long since been regarded as hopeless, it remains worthy of reflection how far, and under what circumstances, we may check its progress. The plant being an annual, its decrease may be effected locally in the same degree as it is prevented from seeding. In garden land this object may be completely attained by out weeding, and on pasture land to a certain extent by close-cropping, or whenever the plant is fully in bloom by mowing — a process which requires to be repeated, in order to destroy the subsequent crops of flowers; but as the plant is rather succulent, it becomes needful to gather what is put in heaps, because when left on the ground it may still ripen its seeds. Trenches and ditches will in a great measure, intercept the influx of its seeds. Where the Cryptostemma is growing in dense masses and its absolute destruction needed, ploughing may be resorted to; but this measure would prove vain unless the ingress of seeds from neighbouring land can be prevented. Probably burning of the dry sward during summer would also destroy much of the Cryptostemma seeds.

Botanical Gardens, Melbourne, Oct. 21.