Neotropical Vivianiaceae

Description

Shrubs, very rarely annual herbs, spine -tipped short-shoots (brachyblasts) often present. Leaves opposite throughout, rarely in whorls of three, simple, mostly ovate and coarsely crenate to pinnatisect to pinnatifid, sometimes tiny (ca. 1-2 mm, on conical short shoots forming little green cones), base cuneate to cordate; estipulate. Inflorescences terminal, thyrsoids or pleiothyrsoids, sometimes apparently single and terminal; inflorescence bracteose or frondose, bracts in Balbisia Cav. often deeply pinnatisect and situated diretly at base of calyx. Flowers hermaphrodite, (4-)5-merous, actinomorphic; sepals well developed, sometimes larger than petals, entire with acute, usually aristate apex; petals 0-4-5, (ob-)ovate to widely circular or obcordate, often apically emarginate, pink, white, or yellow; stamens (4-5)-10, usually obdiplostemonous and heterantherous with typically five long and five short stamens, filaments sometimes with pair of basal appendages; gynoecium of 3-5 carpels, syncarpous with 3-5 locules; style very short, with 3-5 long, papillose stigmatic branches; ovary 3-5-lobed, with 1-20, pendulous, campylotropous ovules in each locule. Nectary disc absent, nectarines sometimes situated on filament appendages. Fruit septicidal or septifragal capsules with 1-8-seeded locules, rarely 5 schizocarps.

Notes on delimitation

• Members of the Vivianiaceae have often been placed in Geraniaceae or segregated into two families, Vivianiaceae (Viviania Cav.) and Ledocarpaceae (Balbisia, Rhynchotheca Ruiz & Pav.).
• The three genera are closely allied and are here considered as parts of a single family.
• Vivianiaceae together with Geraniaceae and Melianthaceae s.l. (incl. Francoaceae) make up the core (and possibly only) families of Geraniales.

Distribution in the Neotropics

Vivianiaceae comprise 3 genera and 17 species, all in Southern South America. Most of them are found in semi-arid areas on the western side of the Andes in South America; only Rhynchotheca is endemic to interandean valleys of Peru and Ecuador, where it is found in cloud-forest remnants (e.g. hedges).

• Rhynchotheca (1 species) -  Peru, Ecuador.
• Balbisia (11 species) - Chile, Peru, Bolivia, Argentina.
• Viviania (5 species) - Chile, 1 in Argentina, Uruguay, S Brazil.

Distinguishing characters (always present)

• Predominantly shrubs, often with spines.
• Soft pubescence usually present.
• Flowers very similar to Geraniaceae.
• Sepals with aristate tip.
• Ovary superior and mostly 5-lobed (superficially identical to those of Geraniaceae).
• Fruit not falling into mericarpids, apart from Rhynchotheca spinosa Ruiz & Pav.
• R. spinosa with apetalous flowers.

Key differences from similar families

• Similar to Geraniaceae, but always thin-stemmed and densely branched shrubs (1 herb!).
• Leaves ovate in outline and shortly petiolate to subsessile.
• Leaves never palmate.

Number of genera

• 3 genera.

Notable genera and distinguishing features

• Balbisia (11 species): flowers bowl-shaped, with yellow, sometimes yellowish-green or reddish-yellow corolla, fruit capsular,  flower subtended by pair of deeply divided bracts.
• Rhynchotheca (1 species): flowers apetalous, anthers pendulous, 5-parted schizocarp.
• Viviania (5 species): flower campanulate, with white or pink petals, pedicellate without bracts directly at base, fruit capsular.

Status

• All species are native, and some species are narrowly endemic.

General notes

• Hunziker & Ariza Espinar (1973) reduced Wendtia Meyen under Balbisia, this judgement is followed here.
• Viviania has been treated either in a wider sense (Knuth 1912) or segregated into a total of 4 genera (3 monotypic genera Cissabryon Meisn., Caesarea Cambess. and Araeoandra Lefor, Lefor 1975).
• The segregate genera of Lefor (1975) may or may not be natural entities, but Viviania s.l. including the segregates appears to be a natural unit and a single genus seems amply sufficient to accommodate its 6 species.
• Rhynchotheca may be the only anemophilous species of Geraniales; its schizocarpic fruits resemble those of Geraniaceae, but are apparently homoplasious.
• Viviania has nectar -flowers, whereas Balbisia is nectarless and has pollen flowers (Weigend 2005).

Important literature

Ariza Espinar, L. 1995a. Flora Fanerogámica Argentina Fasciculo 8, 129b. Vivianiaceae. - Córdoba (Argentina): CONICET.

Ariza Espinar, L. 1995b. Flora Fanerogámica Argentina Fasciculo 18, 129a. Ledocarpaceae. - Córdoba (Argentina): CONICET.

Boelcke, O. 1989. Plantas Vasculares de la Argentina. Buenos Aires: Editorial Hemisferio Sur S.A.

Brako, L., & Zarucchi, J. L.1993. Catalogue of the Flowering Plants and Gymnosperms of Peru. Monogr. Syst. Bot. Missouri Bot. Gard. 45.

Correa, N.M. 1988. Flora Patagonica V - Dicotyledones dialipétalas. Buenos Aires: INTA.

Hunziker, A.T., & Ariza Espinar, L.1973. Aporte a la rehabilitación de Ledocarpaceae, familia monotipica. Kurtziana 7: 233-240.

Jørgensen P.M., & Yanez León, S. 1999. Checklist of the Vascular Plants of Ecuador. Monogr. Syst. Bot. Missouri Bot. Gard. 75.

Lefor, M. W. M. 1975. 2012. A taxonomic revision of the Vivianiaceae. Univ. Conn. Occ. Papers, Biol. Sc. Ser. 2/15: 225-255.

Plazzesi, L., Gottschling, M., Barreda V. & Weigend, M. 2012. First Miocene fossils of Vivianiaceae shed new light on phylogeny, divergence times, and historical biogeography of Geraniales. Biological Journal of the Linnean Society 107: 67-85.

Price, R.A., & Palmer, J. D. 1993. Phylogenetic relationships of the Geraniaceae and Geraniales from rbcL sequence comparisons. Ann. Missouri Bot. Gard. 80: 661-671.

San Martín, J. 1983. Medicinal Plants in Central Chile. Economic Botany 37(2): 216-227.

Soltis, D. E.,  Soltis, P. S.,  Chase, M. W.,  Mort, M. E.,  Albach, D. C.,  Zanis, M.,  Savolainen, V.,  Hahn, W. H.,  Hoot, S. B.,  Fay, M. F.,  Axtell, M.,  Swensen, S. M.,  Prince, L. M.,  Kress, W. J.,  Nixon, K. C., & Farris, J. S. 2000. Angiosperm phylogeny inferred from 18S rDNA, rbcL, and atpB sequences. Bot. J. Linn. Soc. 133: 381-461.

Weigend, M. 2005. Floral morphology and Pollination in Vivianiaceae (Geraniales). Plant Systematics and Evolution 253: 125-131.

Weigend, M. 2006. Vivianiaceae. In: Kubitzki, K.: The Families and Genera of the Plants IX: 213-220. Springer-Verlag, Berlin, Heidelberg, New York.

How to cite

Weigend, M. (2009). Neotropical Vivianiaceae. 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/Vivianiaceae.htm.