To Charles Duffy¹    9 September 1871

Opinions of the Government Botanist on the proposed alterations in the Thistles Prevention Statute of 9th May 1865.

A, Proceedings of Shires, Boroughs and Road Boards conference.

Section 3.

In as much as the term "prickly thistle" is not scientifically or even popularly recognized, I beg to advise that this clause should be amended as follows:

"In the construction of this act the word "thistles" shall be held to mean and include the plants known by the botanical and vernacular names of Carduus Marianus or Milk or Spotted Thistle, Carduus lanceolatus or Spear Thistle, Carduus arvensis or Creeping Thistle, Carduus palustris or Marsh Thistle, Onopordum Acanthium or Real Scotch Thistle or Cotton Thistle, and Xanthium spinosum or Bathurst Burr; and that the onus or proof that any plant on account of which law proceedings are taken, does not belong to any of those named in the act shall be with the defendant.["]²

It will be observed that the Carduus benedictus mentioned in the act is omitted in this amended clause, that particular plant, the Holy Thistle,³ having lately almost disappeared, it moreover having never been really abundant; but two additional Thistles are now specified, which invaded more lately this colony, probably from Tasmania, where they are long naturalized, and I deem it particularly desirable that these should be included, as both are troublesome, and particularly so the Carduus arvensis⁴ on account of its creeping perennial root, which is very tenacious of life. I may add that all the other thistles can be destroyed by preventing their seeding; and this measure can be effected by cutting or uprooting the plants when coming into flower — which may be required a second time — and burning them; all the thistles now mentioned, except the Creeping Thistle, have roots of only one or two years duration.

In my opinion it is however advisable, that provision should be made in the new act, to add to the list of thistles any other kinds, which may successively find their way into this colony, and which may be deemed by the Government Botanist as sufficiently noxious to be operated against in conformity with this act.⁵

In reference to the Docks, of which two kinds have become frequent in Victoria, namely the Curled Dock (Rumex crispus) and the Clustered Dock (Rumex conglomeratus) I would observe, that it is impossible to destroy them by merely cutting the plants, their roots being of several years or even many years duration, requiring to be dug up. To cut the Docks and to burn the herb before the seeds have ripened will however prevent the further dissemination of these weeds.

Section 9

13, The proposition asked for by Councils or Boards, to lease or let unoccupied lands of absent proprietors for a term so long as even seven years, to recover expenses for destroying thistles, seems a measure of severity, though the leasing of the land would be far preferable to its sale; but it would in my opinion be required to mitigate this power as regards length of time, and also to fix by law the maximum rate of expense for destroying the thistles, such rate not to exceed a fixed sum per acre.

I see no objection to the adoption of the other clauses, proposed by the Conference.

B. Glenlyon, Franklin and Daylesford Agricultural Society.

It seems to me, that it cannot well be made compulsory to destroy under the "Thistle Act" such plants as the Docks and Wireweed, unless the whole scope of the statute is extended, and unless many other troublesome weeds, such as the Burr Clover (Medicago denticulata) the South European Star Thistle (Centaurea Melitensis), Cryptostemum⁶ calendulaceum and many other weeds, were also included in the operations of the act. The thistles are particularly dangerous in spreading, because the seeds by means of their feathery downs are easily and widely blown about, while the prickly fruit of the Bathurst Burr is likewise readily carried from spot to spot, particularly by flocks. It is desirable that Docks should be suppressed, still they do not spread with the facility of Thistles.

C. Mr. McKnights⁷ Propositions.

The proposition of destroying thistles on runs solely through depasturing of sheep is open to this objection, that in very many places the seeds will ripen to be carried from the pastures to agricultural land. At all events it should be compulsory to allow no thistles to grow on pasture land within a certain number of miles from agricultural areas, although even this exemption from the law would not likely prove desirable.

The removal of each separate set of flowers, as suggested, would entail far too much labor.

To exhaust widely the soil for thistles through their own growth seems to me an impossibility, even if thus the impoverishing of the soil was not objectionable in itself. But as already remarked the thistles when uprooted or cut should be collected and burnt, or they might be covered up in holes for decay. Whereever the destruction of the thistles through sheep can be completely effected, there will be no necessity whatever of adopting other measures of eradication, and consequently no occasion will arise for enforcing the Thistle Act.

I am satisfied that the tonic effect, which the thistle may have on sheep, is produced by many other always available herbs.

I see no applicable means to attain the object of depriving the thistles of their successive buds before flowering, by framing and enforcing a clause to that effect in a legal statute. If pastoral areas are to be exempted from the act at all I would suggest certainly that the law of destroying the thistles should be kept with rigour along all the boundary lines of such areas. To effect the destruction of these plants through sheep is assuredly open to any one, who likes to adopt this method.

D, Ballarat Agricultural and Pastoral Society.

1, The name "Prickly Scotch Thistle" is not universally recognized. By adopting along with the botanical name the accepted English vernacular names for the various thistles now common here, all misconceptions are obviated, and yet a clear definition is gained, while the exclusive adoption of vernacular names might lead to legal disputes.

2, All species of real thistles must be injurious to agricultural land, though they may possibly be innocuous on pastoral land. I hold however, that thistles even on runs should be supplanted by more nutritious herbs and by the best perennial grasses; and I believe that by the total suppression of the thistle in favor of more useful plants also the pastoral interests of our colony will be very much advanced.

The thistle florishes in Victoria throughout the year, hence to limit the thistle season from September to May is inadmissible.

All the other clauses suggested by the Society seem to be just and to have a practical bearing.

Ferd von Mueller

9/9/71.⁸

Carduus benedictus

Carduus lanceolatus

Carduus Marianus

Carduus palustris

Centaurea Melitensis

Cryptostemum calendulaceum

Medicago denticulata

Onopordum Acanthium

Rumex conglomeratus

Rumex crispus

Xanthium spinosum