Two new species of Heteranthera (Pontederiaceae) in North America

  • Charles N. Horn Department of Biology, Newberry College

Abstract

Two new species are here described as segregates from Heteranthera multiflora. Heteranthera missouriensis sp. nov. has 5–13 flowers on an elongate floral axis, lavender to purplish flowers, a smaller perianth with the tube 3–5 mm long and lobes 3–4.5 mm long; it is common in the southern Great Plains of North America. Heteranthera pauciflora sp. nov. has 3–6 flowers on a shortened floral axis, commonly enclosed by the subtending spathe, white to light lavender flowers with the tube 8–10 mm long; it is known from the Atlantic coast from New Jersey to North Carolina. A taxonomic key to all species of the genus in North America, and a modified description of Heteranthera multiflora, are provided.

References

GRISEBACH, A.H.R. 1879. Symbolae ad Floram Argentinam. Zweite Bearbeitung argentinischer Pflanzen. Gottingen (Dieterich), Germany.

HORN, C.N. 1985. A systematic revision of the genus Heteranthera (sensu lato; Pontederiaceae). PhD dissertation, University of Alabama, Tuscaloosa, U.S.A.

HORN, C.N. 1986. Typifications and a new combination in Heteranthera (Pontederiaceae). Phytologia 59:290.

HORN, C.N. 1987. Pontederiaceae. In: R. Spichiger, ed. Flora of Paraguay. Conservatoire et Jardin Botaniques, Geneve, Switzerland and Missouri Botanical Garden, St. Louis, U.S.A.

HORN, C.N. 2002. Pontederiaceae, Pickerel-weed Family. In: Flora of North America Editorial Committee, eds. Flora of North America, Oxford University Press, UK. 26:37–46.

PELLEGRINI, M.O. & C.N. HORN. 2017. Two peculiar new species of Heteranthera Ruiz & Pavon (Pontederiaceae) from Brazil, with notes on inflorescences architecture in the family. PhytoKeys 82:35–56. doi: 10.3897/phytokeys.@.13752.

SOUSA, D.J.L. DE, L.Y.S. AONA, & A.M. GIULIETTI. 2018. Heteranthera longirachilla (Pontederiaceae), a misinterpreted new species of the H. reniformis complex. Syst. Bot. 43(2):502–509. doi: 10.1600/036364418X697238.

Published
2020-07-15
How to Cite
Horn, C. N. (2020). Two new species of Heteranthera (Pontederiaceae) in North America. Journal of the Botanical Research Institute of Texas, 14(1), 1-8. https://doi.org/10.17348/jbrit.v14.i1.886