Neotropical Amaranthaceae

Carlos Alberto Agudelo Henao

Universidad del Quindío, Programa de Biología, Centro de Estudios e Investigaciones en Biodiversidad y Biotecnología, Colombia. 

Description

Annual or perennial herbs, subshrubs or shrubs, rarely lianas; plants dioecious, polygamous or monoeciousLeaves simple, alternate or opposite, estipulate, entireInflorescence a dense head, loose or spike-like thyrse, spike, raceme or panicle, basically cymose, bracteate; bracts transparent, membranous, white or other colour, subtending one or more flowers.  Flowers small, hermaphrodite or unisexual, sometimes modified into bristles or sterile, usually actinomorphic, bracteolate; sepals (tepals) usually 3-5, rarely fewer, free, scale-like or membranous; petals absent; stamens usually 3-5, opposite the tepals, free or filaments fused into a tube/cup, anthers 1-2-locular; ovary superior, 2-3-carpellate, 1-locular, placentation basal, 1 style, stigma of variable form.  Fruits few-seeded capsules, nutlets, achenes or berries; seeds black, shiny

Notes on delimitation

  • The Amaranthaceae is considered sister to the Chenopodiaceae with which it is sometimes also united (Giannasi et al. 1992, Rettig et al. 1992, Cuénoud et al. 2002).  Recent molecular studies using the markers rbcL and matK resolve Amaranthaceae-Chenopodiaceae as sister to the Achatocarpaceae (Manhart & Rettig 1994, Savolainen et al. 2000a, Cuénoud et al. 2002, Hilu et al. 2003) and with morphological data (Rodman 1994).

Distribution in the Neotropics

  • The list of genera below include the Amaranthaceae genera reported from Mexico, Central and South America, and the Caribbean.

Distinguishing characters (always present)

  • Plants with simple, estipulate leaves with entire margins.
  • Flowers are small, several clustered in inflorescences.
  • A bract and two bracteoles support a flower.
  • Sepals (tepals) present, free; petals absent.
  • Ovary superior, 2-3-carpellate; placentation basal.

Number of genera

  • 1. Achyrantes L.
  • 2. Alternanthera Forssk.
  • 3. Amaranthus L.
  • 4. Blutaparon Raf.
  • 5. Celosia L.
  • 6. Chamissoa Kunth
  • 7. Cyathula Blume
  • 8. Dicraurus Hook.f.
  • 9. Froelichia Moench
  • 10. Froelichiella R.E.Fr.
  • 11. Gomphrena L.
  • 12. Gossypianthus Hook.
  • 13. Guilleminea Kunth
  • 14. Hebanthe Mart.
  • 15. Herbstia Sohmer
  • 16. Iresine P.Browne
  • 17. Irenella Suess.
  • 18. Lithophila Sw.
  • 19. Pfaffia Mart.
  • 20. Pleuropetalum Hook.f.
  • 21. Pseudogomphrena R.E.Fr.
  • 22. Pseudoplantago Suess.
  • 23. Woehleria Griseb.

Useful tips for generic identification

Key to genera of Neotropical Amaranthaceae

1. Leaves alternate … 2
1. Leaves opposite … 7

2. Fruits with many seeds; flowers bisexual … 3
2. Fruits with one seed; flowers bisexual or unisexual … 4

3. Sepals ovate or suborbicular, obtuse; stigmas 3; seeds more than 10 … Pleuropetalum
3. Sepals lanceolate or elliptic, obtuse or acute; stigmas 2-3; seeds less than 10 … Celosia

4. Scandent herbs or lianes; stamen filaments fused into a cup-shape … 5
4. Erect herb; stamen filaments free at the base … 6

5. Fruits indehiscent or irregularly dehiscent; seeds non-arillate … Herbstia
5. Fruits dehiscing by circumsissile lid; seeds arillate … Chamissoa

6. Flowers surrounded by tufts of trichomes; stamens 5, alternating with ligulate or triangular pseudostaminode … Dicraurus
6. Flowers not surrounded by tufts of trichomes; stamens without pseudostaminodes … Amaranthus

7. Flowers or flower glomerules in elongate spikes or in cymes; stigma capitate … 8
7. Flowers or flower glomerules in cylindrical spikes, simple heads or arranged in complex paniculate or racemose structures; stigma penicillate, bilabiate or bifid … 10

8. Presence of modified sterile flowers; pseudostaminodes alternating with the 5 stamens … 9
8. All flowers fertile and bisexual; pseudostaminodes alternating with the 2-5 stamens … Achyranthes

9. Flowers in glomerule or a many-flowered cyme; flowers sterile; bractoles terminating in a hook … Cyathula
9. Flowers in spikes or cymes; flowers: one bisexual and one sterile with hook-shaped projections … Pseudoplantago

10. Inflorescences in glomerules or axillary spikes … 11
10. Inflorescences in simple or composite panicles, racemes or spikes … 13

11. Glomerules few-flowered; pseudostaminodes present; stigma penicillate … Tidestromia
11. Glomerules many-flowered; pseudostaminodes absent; stigma bilabiate … 12

12. Leaves small, in basal rosette, early caduceus; tepals 5, free; stamens adnate to the tepals; gynoecium perigynousGuilleminea
12. Leaves large, in basal rosette, persistent; tepals 5, connate into a tube; stamens free from the tepals; gynoecium hypogynous … Gossypianthus

13. Sepals basally connate; plants with abundant grey indumentum; fruits with or without appendages … 14
13. Sepals free at base; plants glabrous to densely indumented, but indumentum not grey; fruits without appendages … 15

14. Sepals connate into a tube; fruits winged; flowers shorter than 5 mm … Froelichia
14. Sepals only connate at base; fruits not winged; flowers longer than 8 mm … Frielichiella

15. Stigma penicillate; staminodes ligulate or triangular, apex acute or divided, alternating with the filaments; inflorescences of dense heads or spikes … Alternanthera
15. Stigma bilabiate or bifid; staminodes present or absent, not like Alternanthera; inflorescences of heads, spikes or panicles … 16

16. Stigma bilabiate or broadly emarginated … 17
16. Stigmas bifid … 18

17. Inflorescences of heads; trichomes straight, surrounding the flowers … Pfaffia
17. Inflorescences in long racemes; trichomes S-shaped, surrounding the flowers … Hebanthe

18. Filaments fused into a tube; inflorescences with or without foliolose bracts … 19
18. Filaments only fused at base; inflorescences without foliolose bracts … 20

19. Inflorescences subtended by 2 foliolose bracts; flowers not surrounded by straight trichomes … Gomphrena
19. Inflorescences without foliolose bracts; flowers surrounded by straight trichomes … Pseudogomphrena

20. Inflorescences in globose or cylindrical spikes or heads; flowers bisexual, not surrounded by trichomes; pseudostaminodes absent ... 21
20. Inflorescences of racemes; flowers bi- or unisexual, with or without trichomes; pseudostaminodes present or absent … 22

21. Plants creeping; leaves fleshy, linear or lanceolate; stamens 5 … Blutaparon
21. Plants erect; leaves not fleshy nor linear or lanceolat; stamens 2 … Lithophila

22. Flowers unisexual with 5 tepals … 23
22. Flowers bisexual with 4 tepals … Woehleria

23. Flowers not surrounded by trichomes; pseudostaminodes absent; erect herbs; staminate flowers with 1-2 stamens … Irenella
23. Female flowers completely surrounded by a rim of trichome; pseudostaminodes short, triangular; erect herbs or climbing; staminate flowers with 1-5 functional stamens and one rudimentary gynoeciumIresine

Status

  • Native.

Important literature

AGUDELO-H., C.A. 2008. Amaranthaceae. Flora de Colombia No. 23. Instituto de Ciencias Naturales, Universidad Nacional de Colombia. Bogotá D.C. Colombia. 138 p.

AGUDELO-H., C.A. 2008. Amaranthaceae. In: Nuevo Catálogo de la Flora Vascular de Venezuela (Hokche, O., P.E. Berry & O. Huber, eds.), pp. 10-14. Fundación Instituto Botánico de Venezuela. Caracas.

BORSCH, T. 2001. Amaranthaceae. In: Stevens, W.D., C. Ulloa, A. Pool & O.M. Montiel (eds.), Flora de Nicaragua vol. Monogr. Syst. Bot. Missouri Bot. Gard. 85: 56-83.

BURGER, W. 1983.  Amaranthaceae. Fl. Costaricensis. Fieldiana, Bot. 13:142-180.

CUÉNOUD, P., V. SAVOLAINEN, L.W. CHATROU, M. POWELL, R.J. GRAYER & M.W. CHASE. 2002. Molecular phylogenetics of Caryophyllales based on nuclear 18S RDNA and plastid rbcL, atpB, and matK  DNA sequences. American Journal of Botany 89(1): 132-144.

DUKE, J. A. 1961. Amaranthaceae. In: R. E. Woodson, Jr., et al., (eds.). Fl. Panama. Ann. Missouri Bot. Gard. 48:6-50

ELIASSON, U. H. 1987. Amaranthaceae. In: G. Harling & L. Andersson (eds.). Fl. Ecuador vol. 28, pp.1-138. Department of Systematic Botany, University of Gothenburg.

GIANNASI, D.E., G. ZURAWSKI, G.H. LEARN & M.T. CLEGG. 1992. Evolutionary relationships of the Caryophyllidae based on comparative rbcL sequences. Systematic Botany 17:1-15.

HENRICKSON, J. 1987. A Taxonomic Reevaluation of Gossypianthus and Guilleminea (Amaranthaceae). Sida 12(2):307-337.

MARCHIORETTO, M. S., P. G. WINDISCH & J. C. DE SIQUEIRA 2002. Os géneros Froelichia Moench e Froelichiella R. E. Fries (Amaranthaceae) no Brasil. Pesquisas, Bot. 52:7-46.

MEARS, J. A. & W. T. GILLIS 1977. Gomphrenoideae (Amaranthaceae) of the Bahama Island. Jour. Arnold Arb. 58:60-66.

MEARS, J. A. 1967. Revision of Guilleminea (Brayulinea) including Gossypianthus (Amaranthaceae). Sida 3(3):137-152.

MORROS, M.E., TRUJILLO B. & PONCE M. 1990. Descripción del género Amaranthus L. con 3 nuevos registros para Venezuela y consiguiente clave para las especies. Ernstia 58-60:45-51.

MÜLLER K. & T. BORSCH. 2005. Phylogenetics of Amaranthaceae based on matK/trnK sequence data - Evidence from Parsimony, Likelihood, and Bayesian analyses. Ann. Missouri Bot. Gard. 92:66-102.

PEDERSEN, T.M. 1967. Stud. in South American Amaranthaceae. Darwiniana 14(2-3):430-462.

PEDERSEN, T.M. 1976. Stud. sobre Amaranthaceae Suramericanas II. Darwiniana 20(1-2): 269-303.

ROMERO B., T. A. 1975. Los Géneros Venezolanos de las Amaranthaceae. Agron. Trop. 10 (1-4): 345-401.

RUTTER, R. A. 1990. Cat. de plantas útiles de la Amazonía Peruana. Perú: Ministerio de Educación, Instituto Linguístico de Verano, p. 10-336.

SAUER, J. D. 1967. The grain amaranths and their relatives: a revised taxonomic and geographic survey. Ann. Missouri Bot. Gard. 54(2):103-137.

SIQUEIRA, J. C. 1989. Amaranthaceae. In: Fl. do estado de Goiás. Colecáo Rizzo 12:1-44.

SMITH, L. B. & R. J. DOWNS 1972. Amarantáceas. En: Fl. Illustr. Catarinense 1:1-110.

SOHMER, S. H. 1977.  A revision of Chamissoa. Bull. Torrey Bot. Club., 104: 111 - 126

TOWNSEND, C. C. 1993. Amaranthaceae. In: K. Kubitzki. The Families and Genera of Flowering Plants 2:70-91

 

 

How to cite

Henao, C.A.A. (2009). Neotropical Amaranthaceae. 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/Amaranthaceae.htm.

Click images to enlarge


Achyranthes aspera var. aspera. a: flower, b: blanch (Aguirre 200 COL). Achyranthes aspera var. pubescens. c: flower, d: branch(Agudelo-H. 2868 COL, HUQ) © Agudelo H., C.A. Amaranthaceae. Flora de Colombia. No. 23. Instituto de Ciencias Naturales, Universidad Nacional de Colombia. Bogotá D.C. Colombia. 138 p.



Alternanthera brasiliana © Denise Sasaki, Programa Flora Cristalino.



Alternanthera brasiliana © Daniela Zappi, RBG, Kew.



Alternanthera caracasana (caption included in the illustration) © Eliasson, U.H. 1987. Amaranthaceae. Págs 1-138. En: G. Harling & L. Anderson (eds.). Flora of Ecuador.



Alternanthera porrigens (caption included in the illustration) © Eliasson, U.H. 1987. Amaranthaceae. Págs 1-138. En: G. Harling & L. Anderson (eds.). Flora of Ecuador.



Alternanthera ramosissima © Leandro Freitas, Jardim Botânico do Rio de Janeiro.



Alternanthera ramosissima © Leandro Freitas, Jardim Botânico do Rio de Janeiro.



Blutaparon vermiculare. a: inflorescence, b: branch, c: flower (García-Barriga 21222 COL). Blutaparon portulacoides. D: inflorescence, e: branch, f: androecium, g: gynoecium (Saravia 473 COL) © Agudelo H., C.A. Amaranthceae. Flora de Colombia. No. 23. Instituto de Ciencias Naturales, Universidad Nacional de Colombia. Bogotá D.C. Colombia. 138 p.



Celosia argentea var. argentea. a: inflorescence, b: open flower, c: tepal, d: gynoecium. Celosia argentea var. cristata. e: inflorescence. © Agudelo H., C.A. Universidad del Quindío, CIBUQ, Herbario HUQ.



Chamissoa altissima (caption included in the illustration) © Eliasson, U.H. 1987. Amaranthaceae. Págs 1-138. In: G. Harling & L. Anderson (eds.). Flora of Ecuador.



Cyathula achyranthoides. a: inflorescence, b: top two flowers in two levels and uncinate bracts, c: open flower (Romero-Castañeda 3779 COL). Cyathula prostrata. d: inflorescence, e: top with flowers in one layer only and uncinate bracteoles, f: open flower (Díaz-Piedrahita 3421 COL) © Agudelo H., C.A. Amaranthceae. Flora de Colombia. No. 23. Instituto de Ciencias Naturales, Universidad Nacional de Colombia. Bogotá D.C. Colombia. 138 p.



Dicraurus leptocladus (caption included in the illustration) © Eliasson, U.H. 1988. Floral Morphology and Taxonomic Relations among the genera of Amaranthaceae in the New World and the Hawaiian Islands. Bot. J. Linn. Soc. 96:235-283



Gomphrena sp. (caption included in the illustration) © Eliasson, U.H. 1987. Amaranthaceae. Págs 1-138. En: G. Harling & L. Anderson (eds.). Flora of Ecuador.



Gomphrena incana © William Milliken, RBG, Kew.



Herbstia brasiliana (caption included in the illustration) © Eliasson, U.H. 1988. Floral Morphology and Taxonomic Relations among the genera of Amaranthaceae in the New World and the Hawaiian Islands. Bot. J. Linn. Soc. 96:235-283.



Irenella (caption included in the illustration) © Eliasson, U.H. 1987. Amaranthaceae. Págs 1-138. En: G. Harling & L. Anderson (eds.). Flora of Ecuador.



Lithophila muscoides (caption included in the illustration) © Eliasson, U.H. 1988. Floral Morphology and Taxonomic Relations among the genera of Amaranthaceae in the New World and the Hawaiian Islands. Bot. J. Linn. Soc. 96:235-283.



Pfaffia sp. © Daniela Zappi, RBG, Kew.



Pfaffia denudata © Daniela Zappi, RBG, Kew.



Pfaffia iresinoides (Asplund 15408). A. Flower head. B, C. Flower with bract and bracteoles seen from lateral (B) and abaxial C. sides. D. Bracteoles seen from lateral sides, one also shown from the abaxial side. E. Bract seen from abaxial side. F. Tepals (pubescence omitted). g. Filament tube. The anthers have been shed. H. Part of opened filament tube seen from the inner side. J. stamen seen from the abaxial side. K. pistil. L. Stigma from other flower than that in K. © Eliasson, U.H. 1987. Amaranthaceae. Págs 1-138. En: G. Harling & L. Anderson (eds.). Flora of Ecuador.



Pfaffia iresinoides © William Milliken, RBG, Kew.



Pfaffia minarum © William Milliken, RBG, Kew.



Pfaffia minarum © William Milliken, RBG, Kew.



Pleuropetalum pleiogynum. a: inflorescence, b: flower, c: sepal, d: fruit (Gentry 15294 COL). Pleuropetalum sprucei. e: inflorescence, f: fruit (Killip 34783 COL) © Agudelo H., C.A. Amaranthceae. Flora de Colombia. No. 23. Instituto de Ciencias Naturales, Universidad Nacional de Colombia. Bogotá D.C. Colombia. 138 p.



Pseudogomphrena scandens (caption included in the illustration) © Eliasson, U.H. 1988. Floral Morphology and Taxonomic Relations among the genera of Amaranthaceae in the New World and the Hawaiian Islands. Bot. J. Linn. Soc. 96:235-283.



Pseudoplantago friesii (caption included in the illustration) © Eliasson, U.H. 1988. Floral Morphology and Taxonomic Relations among the genera of Amaranthaceae in the New World and the Hawaiian Islands. Bot. J. Linn. Soc. 96:235-283.



Woehleria serpyllifolia (caption included in the illustration) © Eliasson, U.H. 1988. Floral Morphology and Taxonomic Relations among the genera of Amaranthaceae in the New World and the Hawaiian Islands. Bot. J. Linn. Soc. 96:235-283.