Nyctaginaceae Juss.

Nyctaginaceae, Hutchinson and Dalziel. Flora of West Tropical Africa 1:1. 1954

Morphology General Habit

Herbs, shrubs or trees

Morphology Leaves

Leaves alternate or opposite, simple; stipules absent

Morphology Reproductive morphology Flowers

Flowers actinomorphic, hermaphrodite or unisexual, usually cymose, sometimes surrounded by brightly coloured bracts, the latter occasionally simulating a calyx

Morphology Reproductive morphology Flowers Calyx

Calyx tubular, often petaloid, valvate or folded in the bud

Morphology Reproductive morphology Flowers Corolla

Petals absent

Morphology Reproductive morphology Flowers Androecium

Stamens 1 to many, hypogynous, free or connate at the base, involute in bud; anthers 2-celled, opening lengthwise

Morphology Reproductive morphology Flowers Gynoecium

Ovary superior, 1-celled; style slender; ovule solitary, erect and inverted

Morphology Reproductive morphology Fruits

Fruit indehiscent, enclosed in the persistent base of the calyx, often glandular

Morphology Reproductive morphology Seeds

Seeds with copious or scanty endosperm and straight or curved embryo

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

Morphology

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 basal ,  ovule 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 .

General Description

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.

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).
• Boerhaviatuberosa Lam. has been consumed as a vegetable in parts of Peru.

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)

Distribution

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.

Diagnostic

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 accrescentperianth tube, with a single seed (anthocarps).

Other important characters

• Ovarysuperior.
• Perianth covered with hairs.
• Anthocarps with various numbers of ribs.

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.

Notable genera and distinguishing features

• Boerhavia - anthocarp 3-5 ribbed, glabrous or glandularpubescent.
• Bougainvillea - involucre of 3 strikingly coloured bracts (seldom greenish).
• Commicarpus - anthocarp with several conspicuous wart-like viscidglands.
• Guapira - stamens and stigmaexserted; 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, sterileapex of the fruit often elongated (rostrum).

Useful tips for generic identification

See below.

Literature

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.