Ruellia tuberosa L.
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Authority
Britton, Nathaniel L. Flora Borinqueña.
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Family
Acanthaceae
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Scientific Name
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Description
Species Description - This purple-flowered, herbaceous plant is frequent in the dry, southwestern and eastern parts of Porto Rico, and occurs also on Vieques, growing in sandy or gravelly soil at low elevations in sunny situations. It is attractive when in bloom, but we have not seen it planted in gardens, nor have we found a Spanish name recorded for it; the English name refers to its clusters of long, thickened roots, which are quite characteristic of the species. It has a very wide geographic distribution, throughout the West Indies, in the southwestern United States, and in continental tropical America, and is the type species of its genus. Ruellia, named in honor of the early French herbalist I. de la Ruelle, who lived from 1474 to 1537, is a large genus of perennial herbs and shrubs, some 200 species being included, mostly tropical American. Another of them, the scarlet-flowered Ruellia coccinea, is also illustrated in this work. They have opposite, mostly broad leaves, and large, often showy flowers, borne solitary, or in clusters. The calyx is 5-cleft, or 5-parted, the segments narrow; the corolla is funnel form or salverform, with a spreading, 5-lobed limb, the lobes blunt, or rounded; the 4 stamens are in 2 pairs; the pistil has a 2-celled ovary, and the tip of the style is recurved. The fruit is an oblong or club-shaped, 2-celled capsule, which splits elastically into 2 valves, releasing the flattened seeds. Ruellia tuberosa (tuberous) is a perennial herb, finely hairy, with several spindle-shaped, long roots, the simple or branched stem about 0.6 meter high, or lower. Its broad leaves are from 4 to 10 centimeters long, wavy-margined, narrowed at the base into wide stalks. The flowers are several together in stalked, terminal clusters; the segments of the calyx are narrow and from 12 to 20 millimeters long, the purple corolla 4 to 6 centimeters long, its tube expanded below the limb. The capsule is from 15 to 25 millimeters long.
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Discussion
Many-roots Acanthus Family Ruellia tuberosa Linnaeus, Species Plantarum 634. 1753.