Neotropical Dipsacaceae

D.J. Nicholas Hind

Royal Botanic Gardens, Kew, UK. 

Description

Annuals, biennial or perennial herbs, rarely shrubs. Roots fibrous or sometimes tuberous. Stems glabrous or variously pubescent, sometimes with prickles, often with basal rosettiform leaves, especially when young, or leaves cauline. Leaves opposite or verticillate, exstipulate, sessile, pseudopetiolate or petiolate, bases sometimes connate, sometimes heterophyllous with lower leaves usually simply but upper leaves variously lobed, lamina entire or deeply lobed, laciniate, lyrate-pinnatifid, or 1–2-pinnatisect, margins entire or variously toothed, glabrous or variously pubescent, sometimes the prickles on lower surface (especially on venation). Inflorescences terminal or axillary, of dense cymose capitula, subtended by phyllaries 1–3-seriate, phyllaries free or rarely connate in basal half, flowering occurring at several points in capitulum, or rarely from apparent middle and working outwards (i.e. Dipsacus L.). Capitula appearing radiate/radiant, ovoid or subglobose, hemispherical or cylindrical. Florets hermaphrodite or female, each usually with a basal epicalyx (involucel) of connate bracteoles sometimes expanded into a variously shaped, often scarious, corona and often subtended by a receptacular scale, involucel variously angled or ridged, receptacular scales linear-lanceolate, sometimes spine-tipped, glabrous or variously pubescent; calyx small, cupuliform or divided into 4–5 teeth or of numerous teeth or setae; corollas usually zygomorphic, lobes 4–5, subequal, or corolla 2-lipped, blue, lilac, white, yellow, pink, red, purple; stamens free, 2 or 4, epipetalous, alternating with corolla lobes, and usually conspicuously exserted from corolla, anthers dorsifixed, dehiscing introrsely via longitudinal slits; stigma solitary or 2-lobed; ovary inferior, unilocular, ovule pendent. Fruit dry, indehiscent, enclosed by epicalyx and usually surrounded by persistent calyx, fruit body variously angled (4-), very rarely with an elaiosome at base (Knautia L.); seed 1, endospermic, embryo straight.

Notes on delimitation

  • The family appears to be reasonably naturally delimited, although some floras expand the family concept with the inclusion of the Morinaceae (Morina L.) with its spikes of false verticellasters, and Triplostegiaceae (Triplostegia Wall. ex DC.), with its characteristic double epicalyx. In the Neotropics the three taxa commonly encountered: Dipsacus fullonum L., D. sativus (L.) Honckeny and Scabiosa atropurpurea L., are all easily placed in the family sensu stricto.
  • 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

Only two genera, and three species, have been commonly recorded within the Neotropics:

  • Dipsacus fullonum and D. sativus (both probably cultivated but occasionally naturalized).
  • Scabiosa atropurpurea (often cultivated, and escaped).

Distinguishing characters (always present)

Other important characters

  • The presence of radiate/radiant capitula in most genera is a useful character.
  • In Dipsacus the odd flowering pattern (acropetal/basipetal) is characteristic, along with the distinctly prickly stem and underside of the leaves, together with the connate leaf bases.

Key differences from similar families

Similar families include the Calyceraceae and Compositae in the presence of numerous florets arranged in capitula sometimes with receptacular bracts present.

The Compositae is easily recognized because of the presence of:

  • Included or exserted stamens with connate anthers (vs. stamens exserted with free anthers).
  • Achenes with or without a pappus of scales or hairs (vs. the presence of the involucel and persistent coroniform calyx in the Dipsacaceae).
  • The Dipsacaceae also have either 2 or 4 stamens; the number of stamens in Compositae is rarely reduced to 4.

The Calyceraceae differ from the Dipsacaceae as follows:

  • Stamens in the Calyceraceae are alternating with the corolla lobes whereas they are epipetalous in the Dipsacaceae.
  • Although both the Dipsacaceae and Calyceraceae have persistent calyces those in the Calyceraceae typically become lignified and spiny; those in the Dipsacaceae become cupuliform or divided into a number of setae.
  • An involucel is only found in the Dipsacaceae.
  • Anthers in the Calyceraceae dehisce antrorsely whereas those in the Dipsacaceae dehisce introrsely.

Number of genera

  • The greater part of the family (7 genera and c. 250 spp.) are found in the Old World in Asia, Eurasia and northern Africa. Only tow are found in the Neotropics. Only two are found in the Neotropics.

Useful tips for generic identification

Dipsacus L. is easily recognized by:

Scabiosa L. often possesses:

  • Basal rosette of leaves.
  • The leaves are heteromorphous with entire or toothed lower leaves and pinnatifid cauline leaves.
  • Typically radiate/radiant capitula.

Status

  • Both representatives of the family found in the Neotropics have been/are cultivated in a number of countries, and have naturalized.

Important literature

Caputo P, Cozzolino S. (1994). A cladistic analysis of Dipsacaceae (Dipsacales). Pl. Syst. Evol. 189. (1-2): 41-61

Nash, D.L. 1976. Dipsacaceae. Flora of Guatemala. Fieldiana, Bot. 24. (11 no. 4): 275 - 431 (1976) p.306.

Verlaque, R. (1984). Etude biosystematique et phylogenetique des Dipsacaceae: 1. Delimitation des Dipsacaceae a l'interieur des Dipsacales, rapports avec les autres familles de l'ordre. (Biosystematic and phylogenetic study of Dipsacaceae: 1. Delimitation of the Dipsacaceae and their relations with other families of the Dipsacales.) Rev. Gen. Bot., 91. (1079-1080-1081): 81-121.

Verlaque, R. (1985). Etude biosystematique et phylogenetique des Dipsacaceae: 2. Caracteres generaux des Dipsacaceae. (Biosystematic and phylogenetic study of the Dipsacaceae: 2. Fundamental characters of the Dipsacaceae.) Rev. Cytol. Biol. Veg. Bot., 8. (2): 117-168 (1985)

How to cite

Hind, D.J.N. (2010). Neotropical Dipsacaceae. 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/Dipsacaceae.htm.