According to Flora of Tropical East Africa[FTEA]
Burmanniaceae, E.J. Cowley. Flora of Tropical East Africa. 1988
- Small herbs, usually saprophytic, rhizomatous or tuberous, usually lacking chlorophyll
- Leaves alternate, simple, entire, sessile, clasping, often forming a rosette, the cauline leaves often scale-like; venation parallel or obscure
- Inflorescence terminal, branched or reduced to 1 flower, racemose or cymose; bracts small
- Flowers bisexual, regular or irregular, trimerous, often 3-6-angled or 3-winged, the wings decurrent on to the ovary
- Perianth-tube open or constricted at the mouth, persistent or not; outer tepals valvate; inner tepals usually smaller, sometimes absent; tepals sometimes very long, narrowly triangular
- Stamens 3 or 6, inserted at various heights, if 3, then opposite inner tepals; anthers dehiscing transversely or longitudinally, sessile or pendulous, 2-thecous; thecae sometimes divaricate and stipitate on the forked connective, which sometimes has apical and/or basal appendages
- Ovary inferior, 3-locular with axile placentas or 1-locular with parietal placentas, which sometimes detach and become suspended apically; sometimes with globose glands on either side of the placentas; ovules numerous, minute; style included, usually short, filiform to conical, shortly 3-lobed or capitate; stigmas sometimes with long filiform tails
- Fruit a capsule, crowned by remains of perianth, often 3- or 6-ribbed or -winged, opening apically or longitudinally between the placentas
- Seeds numerous, minute, subglobose, linear or ellipsoid; endosperm scanty or none
According to Neotropikey[NTK]
Maas-van de Kamer, H. & Maas, P.J.M. (2009). Neotropical Burmanniaceae.
Small herbs, myco-heterotrophic ("saprophytic") and without chlorophyll, or sometimes autotrophic and with chlorophyll; rhizome mostly present, cylindrical, rarely tuberous, densely covered with scale-like leaves; roots filiform , glabrous . Stems mostly unbranched, variously coloured. Leaves alternate , sessile , simple , entire , in myco-heterotrophic species small and scale-like, in autotrophic species to rather large and often rosulate. Inflorescence a terminal , bracteate, lax to contracted, usually bifurcate, few- to many-flowered cyme , or reduced to 1 flower only. Flowers bisexual , actinomorphic , variously coloured; tepals arranged in 2 whorls, basally connate ; floral tube mostly persistent , sometimes provided with longitudinal wings or ribs; tepals 6, very rarely 3 (Marthella Urb.), the outer ones often much larger than the inner ones; stamens 3, erect , inserted in the floral tube just below and opposite the inner tepals, filaments short, anthers dithecal, introrsely and transversely dehiscent , connective dilated; style 1, cylindric to filiform , equaling the floral tube, 3-branched at the apex , stigmas variously shaped, sometimes provided with filiform appendages; ovary inferior, 1-locular with axile placentation to 3-locular with parietal placentation, often with septal nectaries or with nectaries on top of the ovary ; ovules many, anatropous. Fruit a capsule , longitudinally or transversely dehiscent by slits or valves, or irregularly opening by withering of the fruit wall. Seeds many, small and "dust-like", fusiform to subglobose.
Distribution in the Neotropics
From the southern USA and Mexico in the North to S Brazil and N Paraguay in the South, also in the West Indian Islands:
- Apteria Nutt. - From the southern USA to Bolivia, Paraguay and SE Brazil, also in the West Indies.
- Burmannia L. - From the southern USA to northern Argentina, Bolivia, Paraguay and SE Brazil, also in the West Indies.
- Campylosiphon Benth. - Throughout tropical South America.
- Dictyostega Miers - From Mexico to Bolivia and SE Brazil.
- Gymnosiphon Blume (including Cymbocarpa Miers) - Throughout the Neotropics.
- Hexapterella Urb. - Northern South America and Trinidad.
- Marthella - Trinidad.
- Miersiella Urb. - Throughout tropical South America.
Key differences from similar families
- Could be confused with Triuridaceae, both sharing alternate, scale-like leaves and being almost exclusively myco-heterotrophic ("saprophytic"), but Triuridaceae have flowers with many, free carpels ("apocarpous") and flowers are often unisexual.
- All genera, except for most species of Burmannia, are myco-heterotrophic ("saprophytic") herbs without chlorophyll.
- Reduced, scale-like leaves.
Key to the genera of Neotropical Burmanniaceae
1. Autotrophic ("non-saprophytic") herbs (B. tenella excepted) with green, often rosulate leaves; flowers tubular to salverform (2-25 mm long), distinctly winged or ribbed, the wings running from the top of the floral tube to the ovary. Throughout the Neotropics —Burmannia
1. Myco-heterotrophic ("saprophytic") herbs; flowers rarely ribbed to slightly winged — 2
2. Tepals soon falling off, leaving a naked floral tube — 3
2. Tepals persistent — 4
3. Outer tepals entire; stamens with a distinct filament; flowers salverform, white to purple, 5-14 mm long, basal part slightly winged to ribbed; capsule dehiscent by withering of the wall between the ribs. N South America and Trinidad —Hexapterella
3. Outer tepals 3-lobed; stamens without a filament; flowers salverform, white to pale yellow, 3-15 mm long, basal part rarely winged to ribbed; capsule longitudinally dehiscent or dehiscent by withering of the wall. Throughout the Neotropics —Gymnosiphon (incl. Cymbocarpa )
4. Flowers salverform, 16-28 mm long, purplish blue to white; rhizome tuberous; outer tepals as long as the inner ones. Tropical South America ... Campylosiphon
4. Flowers tubular, infundibular to campanulate; rhizome never tuberous; outer tepals longer than the inner ones — 5
5. Flowers campanulate to infundibular, 6-21 mm long, purple to white; filaments basally decurrent ino a crescent-shaped pouch, and bearing abaxially a 2-lobed wing. S USA and the Neotropics —Apteria
5. Flowers tubular, 2-9 mm long —6
6. Flowers nodding, 2-9 mm long, white to purplish white, or pale yellow; small septal glands present. Mexico to Bolivia and SE Brazil — Dictyostega
6. Flowers erect, three 2-lobed glands present on top of the ovary...7
7. Inflorescence umbelliform; flowers 3-5 mm long, purple to white. Tropical Souh America — MiersiellaNotable genera and distinguishing features
7. Inflorescence capitate; flowers 6-7 mm long, yellowish. Trinidad —Marthella
- Apteria: Very widely distributed from the southern USA in the North to southern Brazil and N Paraguay in the South; its only species (A. aphylla (Nutt.)Barnhart ex Small) is highly variable, particularly in its flower shape and size.
- Burmannia: The most common genus in the family, easily recognizable by its often winged, strikingly coloured flowers and in mostly being autotrophic.
- Gymnosiphon ("naked tube"): Notoriously difficult genus because its drops its tepals already in a very young stage.
- Marthella: Only known from Mount Tucuche in Trinidad, its last collection dating from 1898 (!) and possibly extinct.
- Leaves alternate.
- Inflorescence a terminal, few- to many-flowered cyme or flowers solitary.
- Tepals 6 (except for the very rare Marthella), basally connate.
- Stamens 3, inserted in the floral tube.
- Ovary inferior.
- Fruit a capsule.
- Seeds many, minute (so-called "dust seeds").
- General Description
Number of genera
- Apteria (1 sp.).
- Burmannia (19 spp.).
- Campylosiphon (1 sp.).
- Dictyostega (1 sp.)
- Gymnosiphon (incl. Cymbocarpa) (16 spp.).
- Hexapterella (2 spp.).
- Marthella (1 sp.).
- Miersiella (1 sp.).
- All genera are native.
- Most myco-heterotrophic plant groups in the Neotropics (incl. Thismiaceae and Triuridaceae) are poorly known and much additional field work needs to be conducted.
- For notes on this aspect see Merckx (2008).
Maas, P.J.M., H. Maas-van de Kamer, J.van Benthem, H.C.M. Snelders, and T. Rübsamen. 1986. Burmanniaceae. Flora Neotropica Monograph 42: 1-189.
Maas-van de Kamer, H. 1998. Burmanniaceae. In: K. Kubitzki (ed.), The families and genera of vascular plants 3: 154-164.
Merckx, V. 2008. Myco-heterotrophy in Dioscoreales. Systematics and Evolution. Pp. 1-217. Leuven, Belgium.
First published in Enum. Pl. Javae 27. 1827 (1827)
- 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 2019. 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.