This section is from the book "The Native Flowers And Ferns Of The United States ", by Thomas Meehan. Also available from Amazon: The Native Flowers and Ferns of the United States in Their Botanical, Horticultural, And Popular Aspects.
Stem stout, angled on one side; leaves sword-shaped (three quarters of an inch wide); ovary obtusely triangular with the sides flat; flowers (two and one half to three inches long) short peduncled, the funnel-form tube shortei than the ovary; pod oblong, turgid, with rounded angles. (Gray's Manual of the Botany of the Northern United States. See also Darlington's Flora Cestrica, Wood's Class-Book of Botany, and Chapman's Flora of the Southern United States.)
THE genus to which the Blue Flag belongs was called Iris, which is the Greek name for rainbow, on account of the brilliant hues displayed by the flowers of some of the species. This brilliancy of color is characteristic of all the American species comprised in the genus, and the plant which we are about to examine does special honor to the name. The hues of the flowers of the Blue Flag are not, indeed, exactly those of the rainbow, but they are quite as varied; and in this respect the specific name of the plant, versicolor, is very appropriate. The great beauty of the Iris versicolor has always won admiration, and has frequently called forth happy lines from the poets. Longfellow, with the popular idea of the relationship of our plant to the Lily present in his mind, thus sings of it: " Beautiful Lily, dwelling by still rivers, Or solitary mere, Or where the sluggish meadow brook delivers Its waters to the weir,
Thou laughest at the mill, the whir and worry
Of spindle and of loom, And the great wheel that toils amid the hurry
And rushing of the flume.
Born to the purple, born to joy and pleasance,
Thou dost not toil nor spin, But makest glad and radiant with thy presence
The meadow and the lin.
The wind blows and uplifts thy drooping banner.
And round thee throng and run The rushes, the green yeomen of thy manor,
The outlaws of the sun.
The burnished dragon-fly is thy attendant,
And tilts against the field, And down the listed sunbeam rides resplendent
With steel-blue mail and shield.
Thou art the Iris, fair among the fairest,
Who, armed with golden rod, And winged with celestial azure, bearest
The message of some god.
Thou art the Muse, who, far from crowded cities,
Hauntest the sylvan streams, Playing on pipes of reed the artless ditties
That come to us in dreams."
The Blue Flag is, indeed, one of the most beautiful of all swamp-loving plants; and a large tract covered with it, while its flowers are in full bloom, as often seen in May or June, is one of the most pleasing sights in nature.
The evident relationship in the poet's mind between our plant and the Lily, and his allusion to the wind which uplifts its "drooping banner," naturally lead us to a consideration of the structure of the flower. In this respect the reflexed sepals, or leaves of the outer division of the perianth, first claim the attention of the student, as they are characteristic of many of the species included in the genus. These sepals turn outward and downward, while in the neighboring order of Amaryllidaceae the floral parts which answer to them have rather an inward direction. From the true Lilies the Iridaceae are widely separated in the natural classification, although the first cause of this wide differentiation is apparently of no great moment. For this very reason the study of the structure of the flower is all the more interesting, as it serves to show on what seemingly small changes hinge the most wonderful divisions of the vegetable kingdom.
It is well to keep a Lily flower in view while studying the manner in which the flower of an Iris is built. In the true Lily the perianth is free from the ovary, which latter is therefore called superior in botanical language; while in the plants of the order Iridaceae the perianth is united to the ovary, which is therefore inferior. (See Fig. 3.) As the Iridaceae as well as the Lilies are endogens, they have their parts in threes in their normal condition. Thus there are three sepals and three petals in the Lily; but in the rhythmical development of growth the two verticils have apparently been arrested together, and both sets are therefore so much alike that there seems to be no distinction between them. It is impossible to tell the sepals from the petals, and it would be quite as correct to say that the perianth of the Lily is composed of six petals, as to say that it is composed of six sepals. In the Iris the perianth also consists of twice three parts, but it is evident that the verticils have been influenced separately. The three leaves which form the lower verticil, and which may be called sepals, although they are purely petaloid, have broad blades and turn downwards; while the second verticil has assumed the shape of comparatively small petals which incline upwards. In the stamens we note a still more remarkable difference between the Lily and the Iris than in the perianth. The Lily has six stamens, and these, like the leaves of the flower-cup, are formed of two verticils of three each. It is difficult, however, to distinguish the two series from one another, as they have both been caught, in very close succession, by the same growth-wave; but if we watch the development of these six stamens, we find that three of the anthers expel their pollen somewhat before the other three, and from this fact we learn that they really represent two stages of growth. The pistil, in like manner, was originally in a ternary condition, but the normally distinct parts have been so united that their trifid character is only revealed by the three-parted stigma at the apex. If now we revert again to the Iris, we shall find but a single verticil of stamens, - three only; but these are in their proper situation, or in other words, they alternate with the petals, and bend back over the median line of the sepals. The other three which we might expect to find, judging from the analogous structure of the Lily, have wholly disappeared. As regards the pistils, they would almost seem to be wanting, at first sight, and in the place which they ought to occupy, we notice a peta-loid, three-parted structure in the centre of the flower, inside of the stamens. On closer examination, however, we discover that these structures are really the pistils, and that they have coalesced with another set of three bodies which might have formed a second verticil of three stamens, but which are still petaloid in character. From the morphological lessons we have already learned, we can now understand what has become of the second verticil of stamens. These organs have evidently been united with the next verticil, or the pistils, and thus we have the beautiful petaloid pistils, which give such a peculiar character to the Iris.
()ur plant abounds in Maine in the East, and in Minnesota in the West, and is as much at home in Arkansas as in Florida, and throughout the whole of the vast territory of which these points indicate the limits.
According to Lindley, the Blue Flag is a "diuretic, purgative, and emetic." Bartram, in his "Travels," tells us that it was in great favor with the Indians as a powerful cathartic; and indeed he intimates that its wide distribution is in a great measure due to the estimation in which it was held by them for medicinal purposes. It has also been found useful in cases of dropsy. In overdoses, it causes nausea, similar to sea-sickness.
1. Flowering stem, proceeding from the terminal bud of a rhizome of last year's growth.
2. Branchlet of the flower stem, with expanded flower.
3. Faded flower.
4. Cross section of the ovary.