Some time ago the “Silverstream,” from Buenos Ayres, discharged a quantity of earth-ballast, which was placed inside the railway-fence on the Bunny Street frontage. A few months later this heap was observed to be covered with a luxuriant growth of weeds, and from it I collected no less than seventeen species—many of them, unfortunately, already too well known in the colony; but two or three have, apparently, not been previously recorded here. Amongst these last was the subject of the present note—viz., Xanthium strumarium, known in England as the small burdock, or burr-weed; in America as the clot, or cockle burr; and in Australia as the Noogoora burr, from the locality where it was first observed to be injurious.

The plant belongs to the order Compositæ, but the young botanical student would probably at first, on account of the separation of the male and female flowers, have some difficulty in understanding why it should be so classed; a further and careful examination will, however, convince him of its true relationship.

Xanthium, Linn. (From [ unclear: ] αv [ unclear: ] ó [ unclear: ] , yellow; the plants being formerly used by the Greeks to dye their hair.)

Capitula unisexual, monœcious; staminate globose, in terminal clusters; pistillate 2-flowered, chiefly axillary. Male capitula with few narrow involucral bracts; florets numerous, sheathed by folded hyaline paleæ; corolla 5-toothed; anthers free or nearly so, base obtuse. Female capitula with an ellipsoidal or ovoid closed gamophyllous aculeate involucre, 2-lobel-late and 2-rostrate; corolla none; achenes solitary in each cell of the indurated prickly enclosing involucre. Coarse, scabrid, hoary, or glabrate annuals, with alternate petiolate palmately-lobed leaves.

X. strumarium, Linn.—Stem, branches, and leaves puberu-lous without spines, mottled, spreading, attaining a height of 6ft. or 8ft. Leaves deltoid, 3- to 5-lobed, unequally, often coarsely dentate, often over 6in. broad; base 3-nerved, cordate, sinus wide, cuneate into the petiole of 1in. to 6in. Capitula nearly sessile, clustered; fruit ellipsoidal, about ¾in. long, terminating in an erect or somewhat curved beak. (Bailey.)

The female flower-heads are in small axillary clusters of two or three, the male flower-heads being placed above them, at the top of the branchlets. After the pollen has been dispersed, the male flowers soon drop off, and the female flower-heads rapidly develope into oblong burrs, very hard, and thickly studded with hooked spines. On the top of the burr are to be seen two very stout beaks, and within will be found two cells, each with a single seed.

This plant is a rank annual weed, and in Australia grows to a height of 6ft., 8ft., or in some cases 10ft., with wide-

spreading branches. The stems of young plants are mottled with purple.

In the earlier stages of development it is readily eaten by cattle. Mr. Gordon, the Chief Inspector of Stock for Queensland, states that its action is to induce paralysis of the heart, causing death without struggle, and apparently without pain. At Mr. Gordon's suggestion, Dr. Bancroft, of Brisbane, undertook experiments which conclusively proved the poisonous nature of the weed. It was introduced into Queensland with cotton from the Southern States of America.

Each plant produces numerous burrs, which, in sheep country, would, from their nature, cause enormous loss to the wool-grower, by injuring the fibre of his chief product.

The fact of so many injurious plants being found in the ballast of a single ship naturally raises the question, What is the best means of dealing with such rubbish?

I am informed that one Harbour Board has decided all ballast except rock shall be taken out to sea by lighters and thrown overboard.

It has been urged in support of this plan that the salt water will rob the seeds of their vitality; but we know that many seeds, especially those with hard covering, retain their vitality after having been carried enormous distances by ocean-currents, so that throwing ballast into the sea, a few miles at most from land, is only providing for the wholesale distribution of noxious weeds all along the coast.

Failing means of calcining, or chemically treating all ballast so as to destroy the plant life therein contained, I would suggest that each Harbour Board set aside a section of ground, securely fenced, that all ballast be deposited there, and its removal from the dépôt allowed only for ballasting vessels, or for reclamation behind well-built retaining-walls, the reason for this last being that, if used for reclamation under any other conditions, the tide would distribute seeds and other light substances far and wide.

With regard to the ballast dépôt, it will be evident that a very small amount of attention would prevent the weeds growing in such an enclosure from bearing seed, and thus a very considerable source of danger be removed.

It may perhaps be some consolation to state that I find our New Zealand slugs are extremely fond of X. strumarium; so much so, in fact, that, though I carefully transplanted at different times no less than nine plants from the ballast-heap to my garden, made a special enclosure, and took every care to protect the young plants and to guard against the spread of the burrs when they should be formed, I was yet unable to rear a single specimen; the slugs had evidently no sympathy with scientific experiments, or with my desire to grow plants