Neotropical Valerianaceae

D.J. Nicholas Hind

Royal Botanic Gardens, Kew, UK. 

Description

Terrestrial annual, biennial, or perennial herbs sometimes subshrubs or cushion-forming shrubs or shrublets, or climbers or scandent plants, usually with characteristic odour, especially when dry (associated with valeric acid); monoecious, dioecious or gynodioecious. Rootstock fibrous, sometimes rhizomatous, or possessing conical, napiform or fusiform taproots. Stems often hollow, often glabrous, or variously pubescent, sometimes glaucous. Leaves opposite or alternate, whorled or basal, sometimes decussate, exstipulate, simple or pinnatisect, variously shaped, base usually clasping, sessile or petiolate, margins entire or serrate. Inflorescences cymose, usually compound, often densely so, with many small flowers, bracteate. Flowers hermaphrodite or unisexual, sessile or short-pedicellate, usually zygomorphic (especially with funnel-shaped corollas, but symmetrical with rotate corollas) and bilaterally symmetrical. Calyx persistent and often becoming woody in fruit, 0–5-lobed, each lobe of few to many segments, very small in flower and markedly inrolled and imbricate, often enlarging to a pappus on apex of fruit, pappus frequently plumose, sometimes absent. Corollas white, pink red or lilac, or very rarely yellow, funnel-shaped, subsalverform or rotate, corolla tube usually longer than corolla lobes, often bulging on one side, saccate or spurred below; corolla lobes 5; stamens 1–4, usually inserted near base of corolla tube and alternating with lobes, usually exserted from corolla, sometimes included; anthers sessile, on short filaments, or filaments distinct, versatile, 2- or 4- lobed, dehiscing introrsely; stigma 2-fid, 3-fid, or subentire, exserted. Ovary inferior, 3-celled, 1 cell with pendent ovule and other 2 sterile and often much reduced in fruit. Fruit dry and indehiscent, glabrous or variously setuliferous or hairy; seed endospermic with straight embryo.

Notes on delimitation

  • The only apparent delimitation problem appears to be with the inclusion of Triplostegia Wall. ex DC. in the family; it is often placed in its own family within the Dipsacales. It does not pose any problems with delimitation of the Valerianaceae in the New World.
  • In ‘APGII’ (Angiosperm Phylogeny Group, 2003) an expanded Dipsacales was promoted in the ‘Euasterids II’, including a broader concept of the Caprifoliaceae, which encompassed the Dipsacaceae and Valerianaceae known from the Neotropics, along with the Adoxaceae. If sunk into the Caprifoliaceae the Dipsacaceae and Valerianaceae would form very discrete subfamilies. However, in Neotropikey the three families (Caprifoliaceae, Dipsacaceae and Valerianaceae) are treated separately, q.v.

Distribution in the Neotropics

  • Valeriana L. is widespread throughout the Neotropics from Mexico south to Argentina. Most of the other genera in the family are restricted to the high altitude areas of the Andes throughout the region.

Distinguishing characters (always present)

The family is a very natural one characterized by:

  • Thyrsoid inflorescence.
  • Sympetalous asymmetric flowers.
  • Inferior 3-carpellate ovaries, one fertile carpel.
  • A single style.
  • Fruit an achene.
  • In addition, dried members of the tribe Valerianeae have a characteristic odour of valeric acid, although this is absent in the tribe Patrinieae.

Other important characters

  • Modifications of the calyx which, if present, form an often distinctive plumose pappus.
  • Stamen number.
  • Corolla lobe number.

Key differences from similar families

Most recent analyses of the Dipsacales place the Valerianaceae as sister to the Dipsacaceae itself. The easiest character to perhaps separate these two families is the presence of:

  • A characteristic capitulum in the Dipsacaceae surrounded by an involucre of more than 2 bracts, and a fruit surrounded by an epicalyx.
  • In the Valerianaceae a capitulum is never present, and the epicalyx is absent.

Number of genera

  • Eriksen (1989a) reduced all of the South American representatives of the Valerianaceae to one amorphous Valeriana, s.l. She maintained this exceptional lumping in her treatment for the Flora of Ecuador (Eriksen 1989b). Weberling (2001) commented on this and, with the supporting evidence of Backlund & Donoghue (1996), maintained the status of the smaller South American genera together with a more restricted sense of Valeriana.
  • As now accepted, there are between 10–13 genera, and some 350–450 species, worldwide. Mainly distributed in the northern hemisphere, South America, and southeastern South Africa. One or two weedy species found in the Neotropics.

A total of eight genera are recorded for Central and South America:

  • Aretiastrum (DC.) Spach
  • Astrephia Dufr.
  • Belonanthus Graebn.
  • Phyllactis Pers.
  • Plectritis DC.
  • Stangea Graebn
  • Valeriana L. (the largest genus in the family), widespread in both the Old and New World.

Status

  • Centranthus ruber (L.) DC., an Old World species, is reportedly a weed in some areas of South America, as is Valeriana officinalis L.

Important literature

Backlund, A., & Donoghue, M. J. 1996. Morphology and phylogeny of the order Dipsacales. Pp. 1-27. In: Backlund, A., Phylogeny of the Dipsacales. Acta Universitatis Upsaliensis, Uppsala.

Borsini, O. E. (1962). Revisión de las valerianaceas de Brasil. Lilloa 31: 149–170.

Borsini, O. E. (1963). Valerianaceas del estado de Santa Catarina (Brasil). Sellowia 15: 123–136.

Enrech, N.X. de (1992). Valerianaceae. In: G. Morillo (ed.), Flora de Venezuela, (T. Lasser, ser. ed.), vol. 5, part 1: Cucurbitaceae (C. Jeffrey & B. Trujillo), Sabiaceae (J. A. Steyermark), Valerianaceae (N.X. de Enrech). Fondo Editorial Acta Cientifica Venezolana, Caracas. pp. 267. [221–266].

Eriksen, B. (1989a). Notes on generic and infrageneric delimitation in the Valerianaceae. Nordic J. Bot. 9(2): 179–187.

Eriksen, B. (1989b). Fam. 186. Valerianaceae. In: G. Harling & L. Andersson (eds), Flora of Ecuador. Vol. 34. Department of Systematic Botany, University of Göteborg & Section for Botany, Riksmuseum, Stockholm. pp. 59.

Graebner, P. (1899). Beiträge zur Kentniss der süd- und centralamerikanischen Valerianaceae. Bot. Jahrb. Syst. 27: 425–436.

Killip, E. P. (1937). Valerianaceae. In: J. F. Macbride (ed.), Flora of Peru. [Pibl. Field Mus. Nat. Hist.] Fieldiana, Bot. Ser. 13 (Part 6, No. 2): 287–321.

Meyer, F. G. (1951). Valeriana in North America and the West Indies (Valerianaceae). Ann. Missouri Bot. Gard. 38: 377–503.

Meyer, F. G. (1976). Family 181. Valerianaceae. In: R. E. Woodson, Jr., R. W. Schery, & collabs., Flora of Panama, Part. IX. Ann. Missouri Bot. Gard. 63(3): 581–592.

Richardson, I. B. K. (1975). A revison of the genus Centranthus DC. (Valerianaceae). Bot. J. Linn. Soc. 71: 211–234.

Rzedowski, J. & G. C. de Rzedowski. (2003). Familia Valerianaceae. In: Flora del Bajio y de regiones adyacentes. Fasciculo 112. Instituto de Ecologia, Pátzcuaro, Michoacán, México.

Sobral, M. (1999). Valerianaceae. In Flora ilustrada do Rio Grande do Sul, 25. Boletim do Instituto de Biociencias 58, Universidade Federal do Rio Grande do Sul, Porto Alegre. pp. 61.

Weberling, F. (2001). Reappraisal of our current knowledge of the genus Stangea Graebn. (Valerianaceae). Akademie der Wissenschaften und der Literatur, Abhandlungen der Mathematisch-naturwissenschaftlichen Klasse Nr. 2. Mainz. pp. 51.

How to cite

Hind, D.J.N. (2009). Neotropical Valerianaceae. 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/Valerianaceae.htm.