Neotropical Cyclanthaceae

Roger Eriksson

University of Gothenburg, Göteborg, Sweden.
 

Description

Monoecious, perennial, terrestrial or sometimes epiphytic herbs or subshrubs, or herbaceous vines or lianas. Stem very short to long and slender, unbranched or branched, rhizomatous to aerial, usually ± lignified. Leaves spiral, spirodistichous, or orthodistichous; adult leaves with open leaf sheaths, petiolate in most species; leaf blades generally bifid, more seldom bipartite, palmate or entire, unicostate or tricostate. Inflorescence an axillary or terminal, unbranched, pedunculate spadix subtended and initially enveloped by 2-11 conspicuous spathes. Flowers unisexual, densely crowded, generally (subfam. Carludovicoideae) in spirally arranged groups, each group consisting of 1 pistillate flower surrounded by 4 staminate flowers, or (subfam. Cyclanthoideae) in alternate cycles, seldom spirals, of staminate and pistillate units. Staminate flowers in Carludovicoideae usually with marginally situated perianth lobes on abaxial side to all around the receptacle, lobes usually in 1 whorl, rarely in 2 whorls or lacking; staminate flowers in Cyclanthoideae as linear rows of stamens; stamens mostly numerous; anthers basifixed, dithecal and tetrasporangiate, usually longitudinally dehiscent, rarely with a two-phase dehiscence mechanism; filaments basally ± connate and usually swollen into basal bulbs, filaments or basal bulbs rarely lacking. Pistillate flowers in Carludovicoideae free or usually partly connate with each other; tepals 4, free or connate, usually epigynous to perigynous, more seldom almost hypogynous; staminodes 4, flexuously filiform, basally adnate to the tepals; ovary 4-carpellate, unilocular, entirely protruding from or more often ± embedded in the rachis, with 4 parietal, subapical, or apical placentas, or with 1 apical placenta, each placenta bearing numerous anatropous, bitegmic ovules; styles lacking or 4, free or ± concrescent into 1 style; stigmas 4, alternating with the tepals; tepals, styles, and stigmas generally persisting and enlarging during fruit development; pistillate flowers in Cyclanthoideae not discernible, coalescent into cycles (rarely spirals) consisting of double pistillate rows with locules confluent into a continuous ovarian chamber with numerous parietal placentae, each pistillate row having 1 row each of very much reduced perianth, staminodes, and carpels. Fruits in the Carludovicoideae ± fleshy, free or united to a syncarp; in the Cyclanthoideae united to hollow rings (or spirals) filled with seeds. Seeds numerous, small to rather large, flat to terete; embryo straight.

Notes on delimitation

  • Cyclanthaceae is certainly monophyletic, despite considerable morphological and anatomical differences between the subfamilies Cyclanthoideae (monotypic) and Carludovicoideae, and well delimited from the closely related families in Pandanales. Similarities with the unrelated Arecaceae and Araceae are only superficial.

Distribution in the Neotropics

  • Asplundia Harling: S Mexico to Bolivia and SE Brazil, and the Lesser Antilles.
  • Carludovica Ruiz & Pav.: S Mexico to C Bolivia and Venezuela.
  • Chorigyne R.Eriksson: Costa Rica and Panama.
  • Cyclanthus Poit.: S Mexico to NW Bolivia and French Guiana, and the Lesser Antilles.
  • Dianthoveus Hammel & G.J.Wilder: SW Colombia to N Ecuador.
  • Dicranopygium Harling: S Mexico to S Peru and French Guiana, and the Lesser Antilles.
  • Evodianthus Oerst.: S Nicaragua to S Peru and E Brazil, and the Lesser Antilles.
  • Ludovia Brongn.: S Nicaragua to C Peru and French Guiana.
  • Schultesiophytum Harling: S Colombia to C Peru.
  • Sphaeradenia Harling: S Nicaragua to W Bolivia and Venezuela.
  • Stelestylis Drude: Venezuela to French Guiana, and E Brazil (?).
  • Thoracocarpus Harling: Costa Rica to Bolivia and SE Brazil, and the Lesser Antilles.

Distinguishing characters (always present)

  • Leaves with an open leaf sheath.
  • Inflorescence a monoecious, pedunculate spadix with spirally arranged groups consisting of 1 pistillate flower surrounded by 4 staminate ones (subfam. Carludovicoideae) or alternate cycles of pistillate and staminate units (subfam. Cyclanthoideae).

Other important characters

Number of genera

12 genera:

  • Asplundia (ca 100 spp.)
  • Carludovica (4 spp.)
  • Chorigyne (7 spp.)
  • Cyclanthus (1 sp.)
  • Dianthoveus (1 sp.)
  • Dicranopygium (ca 50 spp.)
  • Evodianthus (1 sp.)
  • Ludovia (3 spp.)
  • Schultesiophytum (1 sp.)
  • Sphaeradenia (52 spp.)
  • Stelestylis (4 spp.)
  • Thoracocarpus (1 sp.).

Useful tips for generic identification

Key to genera of Neotropical Cyclanthaceae

1. Leaf blades not plicate, lateral costae ending in apex; staminate and pistillate flowers in alternate cycles (subfam. Cyclanthoideae) ... Cyclanthus
1. Leaf blades plicate, lateral costae absent or ending below apex; staminate and pistillate flowers in spirally arranged groups (subfam. Carludovicoideae) ... 2

2. Leaves arranged in 2 rows (distichous); petiole ± elliptic in c.s.; placentation subapical or apical ... 3
2. Leaves spirally arranged; petiole adaxially flattened; placentation parietal... 6

3. Leaf blades entire... Ludovia
3. Leaf blades bifid ... 4

4. Pistillate flowers and fruits free; placentation subapical ... Chorigyne
4. Pistillate flowers and fruits connate; placentation apical ... 5

5. Placenta one; seeds broadly ellipsoid to narrowly oblong... Sphaeradenia
5. Placentas four; seeds fusiform... Stelestylis

6. Pistillate flowers and fruits free... 7
6. Pistillate flowers and fruits connate... 9

7. Leaf blades tricostate, not scabrous; stamens with basal bulb... Schultesiophytum
7. Leaf blades unicostate or subtricostate, scabrous; stamens ± lacking basal bulb... 8

8. Staminate flowers with perianth lobes in two rows; tepals acute to shortly acuminate; seeds strongly flattened ... Evodianthus
8. Staminate flowers with perianth lobes in one row; tepals-acuminate; seeds somewhat flattened ... Dianthoveus

9. Adult leaves with four segments; fruits in a layer irregularly splitting from rachis... Carludovica
9. Adult leaves with two segments, each segment sometimes secondarily split; fruits not in an irregularly splitting layer ... 10

10. Spathes clustered; seeds terete... Dicranopygium
10. Spathes dispersed; seeds strongly flattened ... 11

11. Spathes diminishing in size upwards; seed coat smooth ... Asplundia
11. Spathes diminishing in size downwards; seed coat striated ... Thoracocarpus

Status

  • The family is endemic to the Neotropics; all species are native, and a few species are also cultivated.

General notes

Cyclanthus form a conspicuous part of the flora in humid areas at low and medium high altitudes throughout the Neotropics. The famous Panama hat is made of leaf fibres of Carludovica palmata Ruiz & Pav. leaves.

Important literature

Eriksson, R. 1989. Chorigyne, a new genus of the Cyclanthaceae from Central America. Nord. J. Bot. 9: 31-45.

Eriksson, R. 1994. Phylogeny of the Cyclanthaceae. Pl. Syst. Evol. 190: 31-47.

Eriksson, R. 1995. The genus Sphaeradenia (Cyclanthaceae). Opera Botanica 126: 1-106.

Hammel, B. E. & Wilder, G. J. 1989. Dianthoveus, a new genus of Cyclanthaceae. Ann. Missouri Bot. Gard. 76: 112-123.

Harling, G. 1958. Monograph of the Cyclanthaceae. Acta Horti Bergiani 18: 1-428, pls 1-110.

Harling, G., Wilder, G. J. & Eriksson, R. 1998. Cyclanthaceae. In: K. Kubitzki (ed.), The Families and Genera of Vascular Plants 3: 202-215, Springer-Verlag, Berlin.

How to cite

Eriksson, R. (2009). Neotropical Cyclanthaceae. 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/Cyclanthaceae.htm.