Neotropical Phytolaccaceae

Victor W. Steinmann

Instituto de Ecología, A.C., Centro Regional del Bajío, Pátzcuaro, Michoacán, Mexico. 

Description

Trees, woody climbers, shrubs or herbs (mostly perennial, sometimes annual), glabrous or with unbranched trichomes, these sometimes gland -tipped.  Leaves alternate, estipulate (but prophylls of axillary buds transformed into spines and resembling stipules in Seguieria Loefl.), usually petiolate, lamina simple, entire, pinnately veined.  Inflorescences mostly of spikes or racemes, rarely of panicles. Flowers hermaphroditic or unisexual with rudiments of the opposite sex, actinomorphic or sometimes weakly zygomorphic (Anisomeria D. Don and Hilleria Vell); perianth in a single whorl, tepals 4 or 5, often persistent, imbricate, free or rarely connate at the base (Hilleria); stamens 3 to many, alternate or irregularly arranged with respect to the sepals, free, anthers bithecal, dorsifixed, introrose or rarely extrorse (Hilleria), with longitudinal dehiscence; ovary superior or rarely semi-inferior (Agdestis Mocino & Sessé ex DC), sessile or rarely on a gynophore (Nowickea J. Martínez & J. A. McDonald), 1-16-locular, locules connate or free, 1-carpellate ovaries with a single basal ovule, multi-carpellate ovaries with axillary placentation and a single ovule in each locule, campylotropous, styles usually free, rarely united or absent, stigmas free, capitate or penicellate. Fruit a berry, samara, drupe or urticle; seeds 1 per locule, perisperm copious to lacking, embryo curved. X=9.

Notes on delimitation

  • Although Phytolaccaceae clearly belongs to the Caryophyllales, there is much debate about its circumscription and exact position.  Some genera historically considered within the family have recently been segregated as separate families.  For example, the North American genus Stegnosperma Benth. is now considered in a monogeneric family Stegnospermataceae, as too are the Old World genera Barbeuia Thouars. (Barbeuiaceae) and Gisekia L. (Gisekiaceae).
  • The New World genera Achatocarpus Triana. and Phaulothamnus A. Gray were recognized by some specialists as members of Phytolaccaceae, but these are now treated in Achatocarpaceae.  Even with these genera removed, controversy exists, and the core of the family is sometimes further divided into two families: Phytolaccaceae (ovary of 3-16 carpels, corresponding to subfamiles Agdestioideae and Phytolaccoideae) and Petiveriaceae (ovary of one carpel, corresponding to subfamilies Rivinioideae and Microteoideae).
  • A definitive conclusion as to their status awaits further comprehensive studies, and the recommendations for a broad Phytolaccaceae are followed here.

Distribution in the Neotropics

  • Agdestis Mocino & Sessé ex DC.: monotypic, occurring in tropical and subtropical habitats from the southeastern United States (Florida and Texas) to Central America; naturalized at least in the Antilles and Brazil.
  • Anisomeria D. Don: three species endemic to Chile.
  • Gallesia Casar.: monotypic, South America in Bolivia, Brazil, Ecuador, and Peru.
  • Hilleria Vell.: three species, northern South America from Colombia and Venezuela to Bolivia and Brazil.
  • Ledenbergia Klotzsch ex Moq.: two species, Mexico to South America.
  • Microtea Sw.: approximately 10 species, Central America and the Antilles to South America.
  • Nowickea J. Martínez & J. A. McDonald: two species endemic to central Mexico.
  • Petiveria L.: monotypic, widespread in tropical and subtropical America from Florida and the Antilles to Argentina.
  • Phytolacca L.: approximately 20 species, subcosmopolitan, nearly 16 species in the Neotropics.
  • Rivinia L.: monotypic, widespread in tropical and subtropical America from the southern United States and the Antilles to Argentina and Chile; naturalized in the Old World.
  • Schindleria H. Walter: two species in Peru and Bolivia.
  • Seguieria Loefl.: 15-20 species distributed from Trinidad to Argentina with the majority of the species endemic to Brazil.
  • Trichostigma A. Rich.: three species distributed from Mexico and the Antilles to Argentina.

Distinguishing characters (always present)

Other important characters

Key differences from similar families

  • Phytolaccaceae can be distinguished from most other Caryophyllalean families by the combination of indeterminate inflorescences (paniculate only in Gallesia and Seguieria) and either unicarpellate ovaries with a single basal ovule or multicarpellate ovaries with axillary placentation and a single ovule in each locule.
  • It is distinguished from Stegnospermataceae by indehiscent fruits (vs. capsules), the absence of petals (vs. petals present), and the lack of an aril on the seeds (vs. arillate seeds).
  • It can be separated from Achatocarpaceae by having either bisexual flowers or unisexual flowers with rudiments of the opposite sex (vs. unisexual flowers lacking rudiments of the opposite sex) and uni- to multiovulate ovaries with the same number of ovules as carpels (vs. a uniovulate ovary formed by 2 carpels).

Number of genera

  • The family contains approximately 16 genera and 75-85 species. Nearly 60 species in 13 genera are present in the Neotropics: Agdestis, Anisomeria, Gallesia, Hilleria, Ledenbergia, Microtea, Nowickea, Petiveria, Phytolacca, Rivinia, Schindleria, Seguieria, and Trichostigma.

Useful tips for generic identification

Key to genera of Neotropical Phytolacaceae

1. Leaves strongly cordate at the base; ovary partially inferior … Agdestis
1. Leaves not cordate at the base; ovary superior... 2


2. Ovary of 5-16 carpels and seeds ... 3
2. Ovary of a single carpel and seed... 5


3. Sepals unequal and somewhat fleshy; carpels distinctly freeAnisomeria
3. Sepals subequal and not fleshy; carpels (at least in the neotropical species) united ... 4


4. Ovary on an elongated gynophoreNowickea
4. Ovary sessile, gynophore absent … Phytolacca


5. Ovary with 2-4 stigmas … Microtea
5. Ovary with a single stigma... 6


6. Flowers slightly zygomorphic, upper tepal free, the lower three tepals connate at the base into a three-lobed lip … Hilleria
6. Flowers actinomorphic, all tepals free... 7


7. Ovary with 4-6 recurved, awn -like protuberances … Petiveria
7. Ovary without protuberances ... 8


8. Inflorescence paniculate; fruit a samara ... 9
8. Inflorescence spiciform or racemose; fruit a drupe or utricle ... 10


9. Plants usually spiny; tepals 5, herbaceous and reflexed in fruitSeguieria
9. Plants unarmed; tepals 4, woody and erect in fruitGallesia


10. Fruit a drupe... 11
10. Fruit a utricle ... 12


11. Stamens 4; stigma capitateRivinia
11. Stamens 8-25; stigma penicillate … Trichostigma


12. Racemes pendulous; bract placed halfway or above between the flower and the base of the pedicel; tepals reticulate veined … Ledenbergia
12. Racemes erect; bract placed at the base of the pedicel; tepals parallel veined … Schindleria

Notable genera and distinguishing features

  • See above

Status

  • All of the genera present in the neotropics are native.
  • Four are strictly endemic: Gallesia, Ledenbergia, Nowickea, and Schindleria.  Seven others extend out of the tropics proper into subtropical America: Agdestis, Anisomeria, Hilleria, Microtea, Petiveria, Seguieria, and Trichostigma.
  • Only Phytolacca is also native to the Old World, but Rivinia is naturalized there.

General notes

  • The greatest diversity of genera and species occurs in the Neotropics, particularly South America.
  • The majority of taxa are herbaceous and most of the woody members have anomalous secondary thickening by means of successive cambia.
  • All of the American genera are present in the Neotropics except Ercilla Adr. Juss. (1 or 2 spp.) which occurs in mesic temperate forests of Chile.
  • Two additional genera are restricted to the Old World: Lophiocarpus Turcz. and Monococcus F. Muell.
  • The family is of little economic importance.  Phytolacca dioica L., ombú tree, is occasionally cultivated in warmer regions of the world, mostly as a fast-growing shade tree having a peculiar trunk and soft, spongy wood.  Petiveria and some species of Gallesia and Phytolacca are used in traditional medicine.  The high saponin content of some species makes them useful for washing clothes, and in eastern Africa Phytolacca dodecandra L'Hér., endod or soap berry plant, is employed locally for this purpose.  This species also has molluscicide properties and is used to control schistosomiasis.
  • The largest and most taxonomically difficult genus is Phytolacca in which species boundaries are often blurred due to widespread hybridization.
  • For a relatively small family, fruit variation is notable with berries, drupes, utricles and samaras present.

Important literature

Burger, W. 1983. Phytolaccaceae, Family 66. In: W. Burger (ed.). Flora Costaricensis. Fieldiana Bot. 13: 199-212.

Elliasson, U.H. 1993. Phytolaccaceae, pp 1-43. In: G. Harling and L. Andersson (eds). Flora of Ecuador vol. 35A. University of Gothenburg, Gothenburg.

Lozada, L. 2000. Phytolaccaceae. In: N. Diego-Pérez and R.M. Fonseca (eds.). Flora de Guerrero 10: 1-20.

Martínez-García, J. 1984. Phytolaccaceae. In: A. Goméz-Pompa (ed.). Flora de Veracruz 36: 1-41.

Martínez G., J. and McDonald, J.A. 1989. Nowickea (Phytolaccaceae), a new genus with two new species from Mexico. Brittonia 41: 399-403.

Nowicke, J.W. 1968. Palynotaxonomic study of the Phytolaccaceae. Ann. Missouri Bot. Gard. 55: 294-364.

Rogers G.K. 1985. The genera of Phytolaccaceae in the Southeastern United States-J. Arnold Arbor. 66: 1-37.

Rohwer, J.G. 1982. A taxonomic revision of the genera Seguieria Loefl. and Gallesia Casar. (Phytolaccaceae). Mitt. Bot. Staatssamml. München 18: 231-288.

Rohwer, J.G. 1993. Phytolaccaceae. Pp. 506-515. In: K. Kubitzki, J.G. Rohwer and V. Bittrich (eds.). The families and genera of vascular plants. Volume 2. Flowering plants. Springer-Verlag, Berlin.

Rzedowski, J. and Calderón de Rzedowski, G. 2000. In: J. Rzedowski and G. Calderón de Rzedowski (eds.). Flora del Bajío y de Regiones Adyacentes 91: 1-32.

Walter, H. 1906. Die Diagramme der Phytolaccacean. Bot. Jahrb. 37 (Beibl. 85): 1-57.

Walter, H. 1909. Phytolaccaceae. In: A. Engler (ed.). Pflanzenreich IV 83 (Heft 39): 1-154.

Walter, H. 1909. Phytolaccaceae. In: A. Engler (ed.). Pflanzenreich IV 83 (Heft 39): 1-154.

How to cite

Steinmann, V.W. (2010). Neotropical Phytolaccaceae. 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/Phytolaccaceae.htm.