Neotropical Lentibulariaceae

Cristina Mercedes Panfet Valdés

Jardin Botanico Nacional de Cuba, Universidade de la Habana, Cuba. 

Description

Plant herbaceous annual or perennial; common in wet places of marsh or wetlands; aquatic, terrestrial or sometimes epiphytic, lacking roots, fixed in moist substrate or free-floating, vascular system often reduced, mostly carnivorous. Stem short; hairs sessile to stalked, glandular -headed, some secreting mucilage and others digestive enzymes. Leaves alternate or sometimes whorled, often in basal rosettes (Pinguicula L., Genlisea A.St.-Hil.), entire to much divided, heterophyllous in different periods of the development of the plant, many Pinguicula and other species (especially sub-tropical species) depend on seasonal climate changes for the regular development of winter rosettes, the leaves of which differ from the summer rosettes. Leaves always highly modified, flat and densely covered with sticky, mucilage-secreting and digestive hairs, and with margins rolling inward in response to contact of glandular hair with prey organism (Pinguicula), or tubular and spiralled, with downward-pointing and digestive hairs and a basal chamber (Genlisea), often dimorphic in aquatic plants (Utricularia L.), with finely divided submerged leaves and traps of complex structure; in winter, subtropical species of Utricularia and Pinguicula develop special organs in axes of branches (hibernacula), air leaves forming floating rosettes around floral peduncle (floats), reduced to scales, or absent in some terrestrial forms, (dimorphism is represented by rosettes of leaves and for insectivorous leaves in ascidio form (traps) (Utricularia) or not obviously foliaceous, highly dissected, bearing prey-catching bladders, each with 2 sensitive valves forming a trapdoor entrance, which opens inward in response to a stimulus conveyed by 4 sensory hairs and then immediately closes again, and lined on inside with branched digestive hairs (Utricularia), stipules lacking or tubular and inserted within the soil substrate (Genlisea), in Pinguicula  leaves without special structures for the capture of prey, surface is covered with sessile or peduncular glands. Inflorescences indeterminate, on scape, terminal, sometimes reduced to a single flower. Flower bisexual, bilateral, bracteate in clusters or single on a scape, zygomorphic; sepals (2), 4 or (5) lobed or divided, distinct to connate, often 2-lipped; petals 5 lobed, connate at the base; corolla 2-lipped, lower lip usually with a nectar spur or sac in some cases (in Pinguicula a regular palate develops where it is seldom possible to see interior of the tubular, personate flower, lobes imbricatesuperior lip very variable; stamens 2, filament adnate to corolla, anthers unilocular, epipetalous in base of corolla tube, anthers 1-locular, longitudinally dehiscent, pollen grains tricolporate to multicolporate; carpels 2, connate, style 1 or commonly obsolete with stigma 2-lobed or a small open lobe and another in parasol form covering stamen, ovary superior, with free central (or basal) placentation; ovules usually numerous, with 1 integument and a thin-walled megasporangium; nectar disk lacking, and nectar produced by corolla nectar spur. Fruit usually circumcissile, loculicidal, or irregular dehiscent for 2-4 valves, numerous seeds, embryo ± undifferentiated, endosperm lacking.

Notes on delimitation

  • Lentibulariaceae are clearly monophyletic, as evidenced by morphology and rbcl sequences (Chase al. 1993, Cieslak et al. 2005) although their exact phylogenetic placement within Lamiales is problematic.
  • There are surprising differences in leaf form between Pingicula, Genlisea and Utricularia. However, the leaves of all three genera have glandular hairs that secrete both digestive enzymes and mucilage, a more or less unmodified leaf bearing gland -headed hairs may represent the ancestral condition. In Utricularia the hairs on the inside of the bladder also remove excess water from the lumen, which is then secreted by external glands.
  • The showy (yellow, white, blue, purple), bilateral flowers are pollinated by nectar -gathering bees and wasps.
  • In Utricularia the stigma is sometimes sensitive (closing when touched).
  • Outcrossing is characteristic.

Distribution in the Neotropics

Cosmopolitan, widespread, occurring from tropical to boreal regions. Neotropic:

  • Utricularia has a centre of diversity in tropical region of South America (Brazil, Venezuela, Guyana).
  • Pinguicula has a centre of diversity in tropical region of Centra America (Mexico).
  • Genlisea is present in Brazil, Mexico and Greater Antilles (Cuba). (Alain, Hno. 1957, Wood, C. E. & al. 1957, Casper, 1966, Adams, C. D. 1972, Temple, P. 1989, Alain ["Liogier A.H."], 1994, Alain ["Liogier A.H."], 1995).

Distinguishing characters (always present)

  • Carnivorous plants of wetlands, aquatic habitats, and moist forest.
  • Leaves always highly modified, that is, flat and densely covered with sticky, mucilage-secreting and digestive hairs.
  • Hairs sessile to stalked, glandular -headed, some secreting mucilage and others digestive enzymes.
  • Flower bisexual, bilateral, bracteate in clusters or single on a scape, zygomorphic.
  • The corolla 2-lipped, the lower lip usually with a nectar spur or sac.
  • Stamens 2, filament adnate to corolla
  • Anthers unilocular, epipetalous in the base of the tube of the corolla, longitudinally dehiscent.
  • Carpels 2, connate, style 1 or commonly obsolete with stigma seated 2-lobed or a small open lobe and one in parasol form covering the stamen.
  • Ovary superior, with free central (or basal) placentation.
  • Ovules usually numerous, with 1 integument and a thin-walled megasporangium.
  • Nectar disk lacking, and nectar produced by corolla nectar spur.
  • Fruit usually circumcissile, loculicidal, or irregular dehiscent with 2-4 valves.
  • Numerous seeds, embryo ± undifferentiated, endosperm lacking.

Other important characters

  • Flower tubular, personate and often with a bulge obscuring the throat.
  • Pollen grains tricolporate to multicolporate.
  • Some species of Pinguicula and Utricularia are epiphytes or hemiepiphytes of moist tropical montane forest.

Number of genera

Lentibulariaceae comprise 3 genera and 350 species:

  • Utricularia L. (215 spp.)
  • Pinguicula L. (120 spp., includes cultivated spp.)
  • Genlisea  A.St.-Hil. (15 spp.)

(Fisher, 2004, Judd, et al. 2002)

Useful tips for generic identification

Key to genera of Neotropical Lentibulariaceae

1. Leaves divided into linear segments, rarely in rosette, sepals with two lobes .... Utricularia  
1. Leaves in basal rosette; sepals with 5 lobes .... 2 

2 Lobes of the calyx laciniate; unequal .... Genlisea  
2. Lobes of the calyx deeply 2-lipped .... Pinguicula  

Notable genera and distinguishing features

  • In Pinguicula, insects are caught and digested by sessile and short-stalked mucilage-producing glands on the upper side of rosette leaves (''flypaper traps''). This causes the shiny appearance of the leaves that led to the common name ''butterwort''.
  • The suction trap-bearing genus Utricularia (Taylor, 1989) and the eel-trap bearing genus Genlisea (Cieslak & al. 2005, Fromm-Trinta, 1981; Taylor, 1991).

Status

  • Economic plants: Utricularia (Bladderwort) and Pinguicula (Butterwort) are occasionally grown as ornamental plants.

Important literature

Adams, C. D. (1972). Flowering Plants of Jamaica. Robert MacLehose & Co. Ltd. The University Press, Glasgow.

Alain, Hno (1957). Flora de Cuba 4. Dicotiledóneas: Melastomataceae a Plantaginaceae. Contr. Ocas. Mus. Hist. Nat. Colegio. "De la Salle" 16.

Alain ["Liogier A.H."], (1994). La Flora de la Española. 6. San Pedro de Macorís.

Alain ["Liogier A.H."], (1995). Descriptive Flora of Puerto Rico and Adjacent Islands. Vol. IV. (ed.) de la Universidad de Puerto Rico. Río Piedras.

Casper, S. J., (1966). Monographie der Gattung Pinguicula L. Bibliotheca Botanica. 127/128, 1-225.

Chase, M. W., D. E. Soltis, R. G. Olmstead, D. Morgan, D. H. Les, B. D. Mishler, M. R. Duvall, R. A. Price, H. G. Hills, Y.-L. Qiu, K. A. Kron, J. H. Rettig, E. Conti, J. D. Palmer, J. R. Manhart, K. J. Sytsma, H. J. Michaels, W. J. Kress, K. G. Karol, W. D. Clark, M. Hedre´n, B. S. Gaut, R. K. Jansen, K.-J. Kim, C. F. Wimpee, J. F. Smith, G. R. Furnier, S.H. Strauss, Q.-Y. Xiang, G. M. Plunkett, P. S. Soltis, S. Swensen, S. E.Williams, P. A. Gadek, C. J. Quinn, L. E. Eguiarte, E. Golenberg, G. H. Learn, JR., S. W. Graham, S. C. H. Barrett, S. Dayanandan, & V. A. Albert. (1993). Phylogenetics of seed plants: an analysis of nucleotide sequences 168 SYSTEMATIC BOTANY, volume 28 from the plastid gene rbcL. Annals of the Missouri Botanical, Garden 80:528-580.

Cieslak, T., Polepalli, J. S., White, A., LLer, K. M., Borsch, T., Barthlott, W., Steiger, J., Marchant, A. & Legendre, L. (2005) . Phylogenetic Analysis of Pinguicula (Lentibulariacea): chloroplast DNA Sequences and morphology support several geographically distinct radiations. American Journal of Botany 92(10): 1723-1736.

Fisher, E., Barthlott, W., Seine R. & Theisen, I. 2004. Lentibulariaceae. Pp. 276-282 en: Kubitzki, K. (ed.), The families and genera of vascular plants, 7. Berlin.

Fromm-Trinta, E. (1979). Revisão das espécies do gênero Genlisea A.St.-Hil. (Lentibulariaceae) das regiõnes Sudeste e Sul do Brasil. Rodriguesia. 31: 17-139.

Judd, J., Campbell, W.S., Kellogg, C.S., Stevens, P.F., Kellogg, E.A. & Donoghue, M.J. (2002). Plant Systematics - A Phylogenetic Approach. Sinauer Associates, Inc., Sunderland, MA.

Juniper, B. E., Robins, R. J. & Joel, D. M. (1989). The Carnivorous Plants. Academic Press, London, UK.

Lloyd , F. E. (1942). The carnivorous plants. Chronica Botanica, Waltham, MA.

Taylor, P. (1989). The genus Utricularia: A taxonomic monograph. Kew. Bull., Add, Ser. 14: 1-724.

Taylor, P. (1991). The genus Genlisea St. Hil.-an annotated bibliography. Carnivorous Plant Newsletter 20: 27-33.

Temple, P. (1989). Carnivorous Plants. The Royal Hoticultural Society. A. Wisley. Handbook. 64 pp.

Wood, C. E. & Godfrey R. K. (1957). Pinguicula (Lentibulariaceae) in the Southeastern United States. Rhodora 59: 217-230.

How to cite

Valdés, C.M.P. (2009). Neotropical Lentibulariaceae. In: Milliken, W., Klitgård, B. & Baracat, A. (2009 onwards), Neotropikey - Interactive key and information resources for flowering plants of the Neotropics. http://www.kew.org/science/tropamerica/neotropikey/families/Lentibulariaceae.htm.