Hottonia inflata Elliott

Featherfoil, Water Violet

© SRTurner

Family - Primulaceae

Habit - Biennial, emergent aquatic forb.

Stem - Submerged and horizontal, to 90 cm, large diameter and internally spongy.

	Stem and leaf bases.
© SRTurner

Leaves - Alternate along submerged stem, clustered in whorl beneath emergent inflorescence. Blades to 10 cm long, sessile or petiolate, pinnately dissected with numerous slender segments.

	Leaves.
© SRTurner

Inflorescence - Emergent sessile umbels of spikelike racemes. Flowers subtended by bracts, arranged in whorls along strongly inflated axis, with 2-10 flowers per whorl. Inflorescence axes to 30 cm long, 1.5 cm wide, ascending at flowering, floating horizontally at fruiting, hollow, conspicuously segmented at nodes, pubescent with minute glandular and nonglandular hairs. Bracts 3-8 mm long, linear.

	Inflorescence.
© SRTurner

	Inflorescence axis.
© SRTurner

	Hollow inflorescence axis.
© SRTurner

Flowers - Actinomorphic, hypogynous, perfect. Flower stalks 3-10 mm long, often with glandular dots or short hairs. Calyces deeply lobed, the lobes 4-9 mm long, 1 mm wide, linear-oblong, with glandular dots or hairs. Corollas 4-5 mm long, white, 5-lobed to below the midpoint, the lobes rounded to bluntly pointed at the tips. Stamens 5, short, the filaments attached in the corolla tube. Ovary unilocular, broadly ovoid to nearly globose, the style short, slender, the stigma club-shaped. Placentation free central.

	Calyces.
© SRTurner

	Flowers.
© SRTurner

© SRTurner

Fruits - Capsules, 2.0-2.5 mm long, pear-shaped to nearly globose, green, membranous, dehiscing longitudinally by 5 valves. Seeds minute, 0.2-0.3 mm long, oblong in outline, the surface with faint lines.

	Fruits.
© SRTurner

	Fruit and bract.
© SRTurner

Flowering - April - July.

Habitat - Swamps, sloughs, ponds, ditches.

Origin - Native to the U.S.

Lookalikes - None.

Other info. - This plant gets my nomination for the most bizzarely cool of all of Missouri's flora. It is found in a handful of counties in the southeastern section of the state. It is widely scattered in the eastern part of the continental U.S., ranging from eastern Texas up through Maine, but is it regarded as uncommon nearly everywhere. In Missouri it is a tracked species, with a conservation rating of S2 (Imperiled).

This is a rarely encountered species. According to Yatskievych's Flora of Missouri, the plant's abundance appears to vary tremendously from year to year. The plant is impossible to mistake for anything else, having several hollow segmented "stems" which are actually inflorescence axes. The visual effect is a bit like a small cactus, but these plants are not spiny and they grow in the opposite sort of habitat. The seeds are dispersed later in the summer, and germinate to form new stems with submerged leaves. These overwinter beneath the water or ice until the following spring, when they produce the strange emergent inflorescences.

The common name "water violet" is inappropriate, since the plants are unrelated to violets. The moniker more commonly refers to a closely related plant, Hottonia palustris, which is native to Eurasia.

Photographs taken at Otter Slough Conservation Area, Stoddard County, MO, 4-22-2019 (SRTurner). Thanks to Stephen Dilks for alerting me to the flowering population.