(Plate VII.)

Family

Pickerel-weed.

Colour

Pinkish blue.

Odour

Scentless.

Range

Mostly in Florida.

Time of Bloom

Summer.

Flowers: growing in thick clusters on a flower stalk. Perianth: labiate; the upper lip three-lobed and beautifully marked with turquoise and sapphire blue, having also a yellow spot in the centre. The lower lip three-lobed and spreading. Stamens: six; the three lower ones in the throat; the three upper ones shorter and imperfect. Pistil: one. Leaves: on petioles; roundish; tipped with a little point and floating in a rosette one to two feet high on the surface of the water. The base of the petiole swollen and filled with air, which keeps the plant from sinking and aids it in resisting both wind and waves. Roots: two feet long; dense, bushy, attaching themselves to the ground where the water is shallow, otherwise floating.

Lining the shores of the St. Johns River and many of the lakes and sluggish streams in Florida, the water-hyacinth may be seen in masses varying from fifty to several hundred feet wide.

The plant is a native of Brazil, and it is thought that it was in about 1890 that it was introduced into Florida. It had been formerly cultivated in northern greenhouses, as it had the potent charm of beauty. So congenial to its tastes did it find the sunny shores of the St. Johns River and the yellowish water that abounds in humid acid and organic matter that it soon laid aside all the customs of a guest, and determined upon dabbling in the political economy and affairs of the country. In streams where sulphur or other distasteful acids are prevalent it is not able to survive.

In 1896 the War Department at Washington was asked to exert its influence with this unruly plant, which was becoming a serious menace to navigation. It has also destroyed bridges, interfered with the timber industry, and affected the health of the region by upholding objectionable organic matter. Great floating masses of the water-hyacinth are moored to the shore by those that have rooted in the shallow water. But at times the wind tears them loose and then large blocks of it go floating about with the current. At one time a strong wind drove it northward until it closed the river for twenty-five miles.

The plant reproduces itself by stolens or leafy shoots and in such numbers that its increase is most alarming. The problem of controlling the water-hyacinth is very interesting. Mechanical means entail such great and continuous expense that it is thought a natural enemy to breed disease amongst it will have to be introduced.