Haigh, A. (2009). Neotropical Juncaginaceae.
Aquatic herbs, emergent, grass-like, underground rhizomes and erect stems usually present. Leaves alternate , basal , simple , sessile ; tubular sheath present, adnate proximally to blade ; ligule present at apex of sheath (a few millimeters long); blades linear , terete to dorsiventrally flattened. Inflorescences terminal on elongate scapes, spikes, solitary pistillate flowers present in Lilaea Bonpl. (in addition to spikes), these axillary . Flowers actinomorphic or zygomorphic , bisexual or sometimes unisexual in Liliaea (plants polygamous); perianth absent, or tepals 1, or 6 in 1-2 series, distinct; androecium of 1, 4, or 6 stamens, sometimes absent, the anthers sessile or subsessile; gynoecium weakly connate in Triglochin L., the ovaries superior , the carpels 3 or 6 (fertile) in Triglochin, or 1 in Lilaea, 3 sterile carpels alternating with fertile carpels when only 3 fertile carpels present (in Triglochin), the styles absent in Triglochin and present in Lilaea; placentation basal , the ovules 1 per carpel . Fruits schizocarps, the 3 or 6 fertile carpels eventually separating into 1-seeded nutlets, the nutlets 3- winged in Lilaea. Seeds solitary; embryo straight.
N.B. Lilaea has up to four types of flowers on one plant. These include perfect flowers with tepals present and the style 0.5-2 mm long or without tepals and the style 0.2-30 cm long. The latter type is solitary in the leaf axils. The remaining ones are in spikes.
Distribution in the Neotropics
A subcosmopolitan family of 4 genera and c. 12 species. Two genera comprising 4 species occur in the Neotropics, and one genus (Tetroncium Willd.) in southern South America.
- Triglochin L.: 12 species, cosmopolitan, with about 4 species native to the coastal marshes of the Neotropics.
- Lilaea: monospecific (L. scilloides (Poiret) Hauman) native to temperate and tropical montane marshes, from Canada to Chile and Argentina.
- Tetroncium Willd.: monospecific (T. magellanicum Willd.) occurs outside the Neotropics, but in Tierra del Fuego, Patagonia, and the Falkland Islands.
Distinguishing characters (always present)
- Aquatic herbs, emergent, grasslike.
- Leaves basal, linear; sheath present.
- Fruits schizocarps or nutlets.
- Flowers with perianth absent, or tepals 1, or 6 in 1 or 2 series.
- Inflorescences on scapes, terminal spikes or of solitary axillary flowers.
Key to genera of Neotropical Juncaginaceae
1. Flowers both distally in scapose, spikelike racemes, these perfect, pistillate and staminate, and basally on the scape in leaf axils, these pistillate and 1-carpellate — Lilaea
1. All flowers distally in spikelike racemes; carpels 3, 4 or 6 — 2
2. Flowers 3-merous — Triglochin
2. Flowers 2-merous; southern S. America —Tetroncium
- General Description
- The Juncaginaceae occupy a variety of habitats. Lilaea can be found in high mountain meadows of the Andes. Triglochin usually occurs in marshes that are brackish or have high concentrations of marl.
- Plants are often extremely abundant in soils so heavily laden with marl or salts that the soil surface is white, especially on high plateaus.
- The Juncaginaceae are placed within the Alismatales with Hydrocharitaceae and Potamogetonaceae.
Haynes, R.R., 2004. Juncaginaceae. Pp. 452-453. In: Smith, N., Mori, S.A., Henderson, A., Stevenson, D.W. & Heald, S.V. (eds.). Flowering Plants of the Neotropics. New York Botanical Garden, Princeton University Press, Princeton.
Haynes, R.R., Les, D.H. & Holm-Nielsen L.B., 1998. Juncaginaceae. In: K. Kubitzki (ed.), The families and genera of vascular plants 4: 260-263.
Juncaginaceae, D. M. Napper. Flora of Tropical East Africa. 1971
- Morphology General Habit
- Annual or perennial herbs
- Vegetative Multiplication Rhizomes
- Rhizomes short or long, or base bulbous; stolons rarely present
- Morphology Leaves
- Leaves basal, linear, flat or semiterete
- Morphology Reproductive morphology Inflorescences
- Inflorescence a spike or raceme
- Morphology Reproductive morphology Flowers
- Flowers regular and bisexual, sometimes imperfect or unisexual
- Morphology Reproductive morphology Flowers Perianth
- Perianth of 6 similar segments in 2 whorls, deciduous, herbaceous; tepals free or connate below
- Morphology Reproductive morphology Flowers Androecium
- Stamens 6, rarely 4, in 2 series opposite the tepals; filaments usually short; anthers 2-thecous, dehiscing longitudinally, extrorse
- Morphology Reproductive morphology Flowers Gynoecium
- Carpels superior, free or axially connate, 6, or 3 + 3 undeveloped, unilocular; ovules 1 or 2, collateral, basal, erect; stigmas sessile or subsessile, plumose or papillose
- Morphology Reproductive morphology Fruits
- Mericarps 3–6, indehiscent, free or axially connate
First published in Gen. Pl. [Jussieu] 43. 1789 [4 Aug 1789] (1789)
- APG IV (2016) http://dx.doi.org/10.1111/boj.12385
Flora of Tropical East Africa
Flora of Tropical East Africa
Kew Names and Taxonomic Backbone
The International Plant Names Index and World Checklist of Selected Plant Families 2021. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
© Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0
Milliken, W., Klitgard, B. and Baracat, A. (2009 onwards), Neotropikey - Interactive key and information resources for flowering plants of the Neotropics.