Neotropical Nyctaginaceae

Leilton Santos Damascena and Alexa Oliveira-Paes Coelho

Universidade Estadual de Feira de Santana, Bahia, Brazil. 

Description

Herbs, shrubs, trees or less often climbers (Bougainvillea Comm. ex Juss.). Roots sometimes fleshy to tuberous. Stem frequently swollen at the nodes, sometimes armed with axillary thorns (Pisonia L.). Stipules absent but trichomes when present, stipitate and viscid-glandular. Leaves opposite, subopposite, rarely whorled or alternate; blades simple and entire to sinuate, glabrous or pubescent, often drying black. Inflorescences terminal or axillary, variously branched but usually ultimate branches cymose, paniculate or sometimes capitate pseudanthia; bracts and bracteoles (1-3) present, sometimes very small and early caducous, calyx-like and subtending a single corolla-like calyx (Mirabilis L.) or corolloid and subtending a cluster of flowers (Bougainvillea). Flowers usually actinomorphic or rarely zygomorphic, hermaphrodite or seldom unisexual (plants then monoecious or rarely dioecious); perianth uniseriate, usually 5-merous; calyx synsepalous, commonly corolloid, forming a well-developed, often slender, elongate, tubular or urceolate tube, the upper part mostly caducous after anthesis, lower part mostly persistent, enclosing mature fruit; lobes (3) 5 (8) herbaceous, carnose or petaloid, induplicate-valvate in bud; corolla absent; stamens as many as calyx lobes, stamens 1-10 (-40), often connate at the base to form short tube, sometimes exserted (Guapira Aubl.), filaments mostly unequal in length; anthers tetrasporangiate, dehiscing by longitudinal slits; intrastaminal annular disc often present around ovary; ovary monocarpellate, unilocular, superior, sometimes stipitate; style long, slender, stigma capitate, penicillate or frimbiate; placentation basalovule 1 per carpel, basal, stipitate, hemianatropous to anacampylotropous. Fruit an achene or thin-walled nutlet, mostly enveloped by persistent variously modified perianth base, forming a so-called anthocarp, or rarely fruit free; anthocarp indehiscent, maturing fleshy, coriaceous or woody, sometimes (Pisonia) provided with one or more vertical series of stipitate glands. Seeds 1 per fruit; exarillate, embryo straight or curved; endosperm absent; perisperm abundant or scanty, mealy, rarely gelatinous.

Notes on delimitation

  • The Nyctaginaceae are placed in the Caryophyllales by all the modern authors.
  • The family is one of the families the Caryophyllideae and as currently circumscribed is closely allied with Phytolaccaceae, especially Petiveria L. which is sometimes segregated as a distinct family, the Petiveriaceae. 
  • Nyctaginaceae and Phytolaccaceae are generally considered to be primitive members of Caryophyllales (sensu Cronquist) and both have been linked to Sarcobatus Nees of the Chenopodiaceae by molecular studies.

Distribution in the Neotropics

  • The Nyctaginaceae are distributed mostly in the tropics and subtropics of the New World and comprise approximately 32 genera and 400 species.
  • Of the 23 genera only Boerhavia L., Commicarpus Standl., Phaeoptilum Radlk., Pisonia and one species of Mirabilis also occur in the Old World.

Distinguishing characters (always present)

  • Sepals united to form a tube.
  • Inflorescences often subtended by conspicuous involucre or flowers sometimes subtended by sepal -like bracts.
  • Corolla absent.
  • Fruits often surrounded by accrescent perianth tube, with a single seed (anthocarps).

Other important characters

Key differences from similar families

Nyctaginaceae and Phytolaccaceae both share a lack petals and have uniovulate locules, but Nyctaginaceae are distinguished by their:

  • Exstipulate, usually opposite leaves.
  • Sepals united to form a tube often resembling a tubular corolla (this sometimes subtended by sepal -like bracteoles).
  • A solitary carpel.
  • Mostly cymose or capitate (vs. racemose or spicate or less often paniculate or cymose) inflorescence often subtended by a conspicuous involucre.

Number of genera

In the Neotropics there are 23 genera and approximately 180 species.

  • Allionia L. (2 species)
  • Andradea Allemão (1 species)
  • Belemia Pires (1 species)
  • Boerhavia L. (20 species)
  • Boldoa Cav. (1 species)
  • Bougainvillea (18 species)
  • Caribea Alain (1 species)
  • Cephalotomandra Karst. & Triana (3 species)
  • Colignonia Endl. (6 species)
  • Commicarpus (25 species)
  • Cryptocarpus Kunth (1 species)
  • Cuscatlania Standl. (1 species)
  • Grajalesia Miranda (1 species)
  • Guapira (70 species)
  • Leucaster Choisy (1 species)
  • Mirabilis (54 species)
  • Neea Ruiz & Pav. (83 species)
  • Neeopsis Lundell (1 species)
  • Pisonia (40 species)
  • Pisoniella (Heimerl) Standl. (1 species)
  • Ramisia Glaz. ex Baill. (1 species)
  • Reichenbachia Spreng. (2 species)
  • Salpianthus Humb. & Bonpl. (1 species)

Useful tips for generic identification

See below.

Notable genera and distinguishing features

  • Boerhavia - anthocarp 3-5 ribbed, glabrous or glandular pubescent.
  • Bougainvillea - involucre of 3 strikingly coloured bracts (seldom greenish).
  • Commicarpus - anthocarp with several conspicuous wart-like viscid glands.
  • Guapira - stamens and stigma exserted; anthocarp smooth.
  • Mirabilis - involucral bracts mostly united; anthocarp 5-10 ribbed.
  • Neea - male flowers with 5-10 included stamens; female flowers usually much smaller than male flowers, with rudimentary stamens.
  • Pisonia - anthocarp coriaceous or woody, smooth or ribbed, with or without prickles, sterile apex of the fruit often elongated (rostrum).

Status

  • Most of the genera are endemic and native to the Neotropics; only Boerhavia, Commicarpus, Phaeoptilum, Pisonia and one species of Mirabilis also occur in the Old World.

General notes

  • The Nyctaginaceae are important only as ornamentals, especially some species of Bougainvillea and Mirabilis (four-o'clocks).
  • Boerhavia tuberosa Lam. has been consumed as a vegetable in parts of Peru.

Important literature

APG II, 2003. An update of the Angiosperm Phylogeny group classification for the orders and families of flowering plants: APG II. Botanical Journal of the Linnean Society 141(4): 399-436.

BEHNKE, H.D. & MABRY, T.J. 1994 (eds). Caryophyllales Evolution and Systematics. Springer-Verlag, Berlin, 334 p.

DALY, C.D. & ROBERTS, A.S. 2004. Nyctaginaceae. In: Flowering Plants of the Neotropics. N. Smith, S.A.Mori, A.Henderson, D.Wm.Stevenson & S.V.Heald (eds). Pricenton University Press. Princeton.

FURLAN, A. 1996. A Tribo Pisonieae Meisner (Nyctagimaceae) no Brasil. Tese de Doutorado. São Paulo: UNESP-Rio Claro.

HUHN, U. & BITTRICH, V. 1993. Nyctaginaceae. In: The Families and genera of Vascular Plants. p: 473-486. K. Kubitzki, J.G. Rohwer, V.Bittrich (eds) Springer.

JUDD, W.S.; CAMPBELL, S. C.; KELLOGG, E. A. & STEVENS, P. F. 1999. Nyctaginaceae. Plant Systematics- A Phylogenetic Approach. p. 313. Sunderland, Sinauer Associates.

STEVENS, W.D., ULLOA, C., POOL, A. & MONTIEL, O.M. Nyctaginaceae Juss. 2001. In: Flora da Nicarágua. VOL. 85. p: 1581-1592. Missouri Botanical Garden Press.

STEYERMARK, J.A., GERALDO, A., AYMARD, C. 2003. Nyctaginaceae In: Flora of the Venezuelan Guayana. Vol. 7. p: 101-118. Berry, P.C., Yatskievych & Holst, B.K. (eds). Missouri Botanical Gardens Press.

How to cite

Damascena, L.S. &  Coelho, A.O.-P. (2009). Neotropical Nyctaginaceae. 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/Nyctaginaceae.htm.