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The convoluted history of the name Lisianthus

Common name: 

Latin name and synonyms: Irlbachia Mart., Nov. Gen. Sp. Pl. 2: 101 (1826 [1827])
Synonym: Pagaea Griseb. in DC., Prodr. 9: 70 (1845)
Synonym: Lisianthus sect. Brachycodon Benth., Hooker’s J. Bot. Kew Gard. Misc. 6: 200 (1854)
Synonym: Brachycodon (Benth.) Progel in Mart., Fl. Bras. 6(1): 229 (1865)

Etymology: Irlbachia is probably named after the town Irlbach (Bavaria, Germany) or a person named Irlbach.

Species: 9 species.

Distribution: Tropical South America, primarily in areas north of the Amazon river in Brazil, Venezuela, Colombia, and Guyana.

Habitat:  Savannas, grasslands, open areas, often on white-sand.  Several species are endemic to the tepui mountains.

Characteristics:   Annual herbs with leaves on the stems or in a basal rosette. Flowers arranged in terminal cymes with long unbranched branches . Bracts scale-like (leaf-like in Irlbachia pumila and I. poeppigii). Flowers 5-merous, actinomorphic with zygomorphic stamens and style. Calyx small, with rounded lobes and fused at least half of their length, with dorsal glandular areas or ridges. Corollas salvershaped, campanulate, or narrowly funnelshaped, often with a short corolla tube, and white, pink, lavender, blue, or purple. Stamens are inserted in the corolla tube close to the base with filaments of equal or unequal length. Anthers are erect or curved with small appendages at the apex. Pollen in polyads, exine with spines or globules. Ovary with glandular disk at the base, style slender, stigma bilamellate. Capsule opening in the middle, often hanging downwards.

Phylogeny and related plants:  Irlbachia is the only genus in the Irlbachia clade in tribe Helieae, and appears to be a rather evolutionary isolated genus  in this tribe. It has unique pollen polyads with a spiny surface.

Economic uses: None recorded.

Notes: Several species that were previously included in Irlbachia are now placed in other genera, such as Adenolisianthus, Calolisianthus, Chelonanthus, Helia, Rogersonanthus, and Tetrapollinia.

Selected species (synonyms in parenthesis) and their distribution:

References and publications: 

Gilg, E. 1895. Gentianaceae. Pp. 50-180. In: A. Engler & K. Prantl, editors. Die natürlichen Pflanzenfamilien, vol. 4(2). Verlag von Wilhelm Engelmann, Leipzig.

Maas, P. J. M. 1985. Nomenclatural notes on neotropical Lisyantheae (Gentianaceae). Proc. Kon. Ned. Akad. Wetensch., Ser. C, 88: 405-412.

Maas, P. J. M., S. Nilsson, A. M. C. Hollants, B. J. H. ter Welle, H. Persoon, & E. C. H. van Heusden. 1983. Systematic studies in neotropical Gentianaceae – the Lisianthius complex. Acta Bot. Neerl. 32: 371-374.

Nilsson, S. 1970. Pollen morphological contributions to the taxonomy of Lisianthus L. s. lat. (Gentianaceae). Sv. Bot. Tidskrift 64: 1-43.

Struwe, L. & V. A. Albert. 1998. Lisianthius (Gentianaceae), its probable homonym Lisyanthus, and the priority of Helia over Irlbachia as its substitute. Harvard Pap. Bot. 3: 63-71.

Struwe, L., J. W. Kadereit, J. Klackenberg, S. Nilsson, M. Thiv, K. B. von Hagen, & V. A. Albert. 2002. Systematics, character evolution, and biogeography of Gentianaceae, including a new tribal and subtribal classification. Pp. 21-309. In: L. Struwe & V. A. Albert (eds.), Gentianaceae: Systematics and Natural History, Cambridge University Press, Cambridge.

Struwe, L., P. J. M. Maas, & V. A. Albert. 1997. Aripuana cullmaniorum, a new genus and species of Gentianaceae from white-sands of southeastern Amazonas, Brazil. Harvard Pap. Bot. 2: 235-253.

Struwe, L., P. J. M. Maas, O. Pihlar, & V. A. Albert. 1999. Gentianaceae. Pp. 474-542. In: P. E. Berry, K. Yatskievych, & B. K. Holst, editors. Flora of the Venezuelan Guayana, vol. 5. Missouri Botanical Garden, St. Louis. (images)

© Lena Struwe, 2003