1. Burmanniaceae Blume

    1. This family is accepted.

[FTEA]

Burmanniaceae, E.J. Cowley. Flora of Tropical East Africa. 1988

Habit
Small herbs, usually saprophytic, rhizomatous or tuberous, usually lacking chlorophyll
Leaves
Leaves alternate, simple, entire, sessile, clasping, often forming a rosette, the cauline leaves often scale-like; venation parallel or obscure
Inflorescences
Inflorescence terminal, branched or reduced to 1 flower, racemose or cymose; bracts small
Flowers
Flowers bisexual, regular or irregular, trimerous, often 3-6-angled or 3-winged, the wings decurrent on to the ovary
Perianth
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
Androecium
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
Gynoecium
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
Fruits
Fruit a capsule, crowned by remains of perianth, often 3- or 6-ribbed or -winged, opening apically or longitudinally between the placentas
Seeds
Seeds numerous, minute, subglobose, linear or ellipsoid; endosperm scanty or none
[NTK]

Maas-van de Kamer, H. & Maas, P.J.M. (2009). Neotropical Burmanniaceae.

Morphology
Description

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
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.
Diagnostic
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.
Other important characters
  • All genera, except for most species of Burmannia, are myco-heterotrophic ("saprophytic") herbs without chlorophyll.
  • Reduced, scale-like leaves.
Useful tips for generic identification

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 — Miersiella
7. Inflorescence capitate; flowers 6-7 mm long, yellowish. Trinidad —Marthella

Notable genera and distinguishing features
  • 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.
Distinguishing characters (always present)
  • 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.).
Status
  • All genera are native.
General notes
  • Most myco-heterotrophic plant groups in the Neotropics (incl. Thismiaceae and Triuridaceae) are poorly known and much additional field work needs to be conducted.
Notes on delimitation
  • For notes on this aspect see Merckx (2008).
Literature
Important literature

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.

Images

Burmanniaceae Blume appears in other Kew resources:

First published in Enum. Pl. Javae 27. 1827 (1827)

Accepted by

  • APG IV (2016) http://dx.doi.org/10.1111/boj.12385

Sources

Flora of Tropical East Africa
Flora of Tropical East Africa
http://creativecommons.org/licenses/by-nc-sa/3.0

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

Neotropikey
Milliken, W., Klitgard, B. and Baracat, A. (2009 onwards), Neotropikey - Interactive key and information resources for flowering plants of the Neotropics.
http://creativecommons.org/licenses/by/3.0