Plumbaginaceae Juss.

Every, J.L.R. (2009). Neotropical Plumbaginaceae.

Morphology

Description

Herbs or shrubs, sometimes scrambling. Secretory glands exuding water, salt or mucilage often present, lepidote indumentum sometimes present. Leaves simple , alternate , spirally arranged, sometimes in basal rosettes, petiolate , membranous or leathery, margin entire or lobed , pinnately veined, glands level with or depressed below the surface; exstipulate . Inflorescences terminal , cymose, in broadly paniculate structures or scorpioid cymes; bracts and bracteoles present. Flowers bisexual , 5- merous , actinomorphic , often heterostylous, floral nodes bracteolate, bracteoles (1-)2; sepals 5, connate , tube 5-10- lobed with spiky, glandular trichomes in Plumbago L.; petals 5, connate into a tube or free , imbricate , clawed, often persistent ; stamens 5, mostly free (Plumbago) or epipetalous at the base of the corolla (Limonium Mill. ) opposite the petals, anthers 2-locular, dehiscent longitudinally; ovary superior with 5 fused carpels, unilocular, styles 1-5, stigmas surmounting the ovary , placentation basal , ovule 1. Fruit an achene , partially or totally enclosed within the persistent perianth , or a five-valved, beaked capsule with a persistent style , normally indehiscent , young fruits sometimes with glandular trichomes. Seeds small, with only the exotesta persisting, sometimes winged .

Distribution

Distribution in the Neotropics

Plumbago (9 species) can be found throughout the Neotropics in dry scrubland, lowland tropical forest and in the Andes:

• Plumbago scandens L. - dry scrubland from Mexico to South America.
• Plumbago caeruela Kunth - Peruvian Andes.
• Plumbago pulchella Boiss. and P. scandens L., P. mexicana Kunth and P. pulchella Boiss. - Mexico.
• P. capensis Thumb. - Caribbean Islands.
• P. indica L. and P. auriculata Lam. - commonly naturalized in the Neotropics.

Limonium (5 species) is to be found in coastal and mountainous areas:

• Limonium bahamense Britton - coastal areas of the West Indies. 
• Limonium haitense Blake - coastal areas of Haiti and Dominican Republic. 
• Limonium brasiliensis (Boiss.) Kuntze - Brazil, Paraguay, Argentina, Uruguay. 
• Limonium peruvianum Kuntze - Peru. 
• Limonium papillatum Kuntze - Isle of Lobos, Peru.

Diagnostic

Key differences from similar families

The following families differ from Plumbaginaceae in having the following features:

Primulaceae:

• Sympetalous.
• Opposite leaves (can also be alternate or basal).
• Axillaryinflorescence.
• Often solitary flowers.

Polygonaceae:

• Tepals. 
• Normally 3-sided fruiting structures, either a nut or achene.
• Conspicuous swollen nodes on the stem.

Frankeniaceae:

• Revolute leaves.
• Pedicels absent.
• Ligule-like appendage present adaxially at petal base.

Other important characters

• Lepidoteindumentum. 
• Secretory glands exuding water, calcium or mucilage.
• Flowers heterostylous.
• Filaments free - Plumbago.
• Filaments basally fused to petals - Limonium.

Distinguishing characters (always present)

• Alternate leaves.
• Inflorescence bracteate, terminal. 
• Flowers pentamerous, actinomorphic, bisexual. 
• Ovule 1.

General Description

Status

• Plumbaga auriculata Lam. (a climber) and P. indica are commonly naturalized in the Neotropics with others cultivated throughout the region. The remainder of the family is native, with some endemic species.

Number of genera

Two Neotropical genera: Plumbago and Limonium.

General notes

• Pollinated by bees, flies and small beetles. 
• From the Latin for lead "Plumbum", so called by Pliny who attributed the curing of lead disease to European species.
• The Caryophyllales are sometimes also called the Centrospermae - meaning "central seeded".

Notes on delimitation

• The Plumbaginaceae are split into two very distinct sub -families: Plumbaginoideae, which includes Plumbago, and Staticoideae, which includes Limonium (Lledo et al. 2001). 
• Treated as a monofamiliar order the Plumbaginales sensu Cronquist.
• Currently placed in the non-core Caryophyllales as a strongly supported monophyletic sister to the family Polygonaceae and in the same clade as Simmondsiaceae, Nepenthaceae and Droseraceae (Lledo et al. 1998, 2001). 
• The Plumbaginaceae have sometimes been placed in the order Primulales, based on similarities in floral structure: both have (1) stamens equal in number to and opposite the petals, (2) common petal-stamen primordia, (3) more or less connatecorolla (Limonium), (4) absence of stipules and (5) superior unilocular ovary with a freebasalplacenta. However, the Primulales have a strongly supported relationship to the asterid 3 clade backed up by cytological and biochemical evidence (Lledo et al. 1998, 2001).

Literature

Important literature

Cuénoud, P., Savolainen, V., Chatrou, L. W., Powell, M., Grayer, R. J., & Chase, M. W. 2002. Molecular phylogenetics of Caryophyllales based on nuclear 18S rDNA and plastid rbcL, atpB, and matK DNA sequences. American J. Bot. 89: 132-144.

Culham, A. 2007. Plumbaginaceae. In: Heywood, V.H., R.K. Brummitt, A. Culham and O. Seberg (eds.). Flowering Plant Families of the World, pp.258-9. Royal Botanic Gardens, Kew.

Kubitzki, K. 1933. Plumbaginaceae. In: Kubitzki, K. (ed.), Families and Genera of Vascular plants vol. 2, pp. 523-530. Springer-Verlag, Berlin.

Lledó, M. D., Crespo, M. B., Cameron, K. M., Fay, M. F., and Chase, M. W. 1998. Systematics of Plumbaginaceae based on cladistic analysis of rbcL sequence data. Syst. Bot. 23: 21-29.

Lledó, M. D., Karis, P. O., Crespo, M. B., Fay, M. F., and Chase, M. W. 2001. Phylogenetic position and taxonomic status of the genus Aegialitis and subfamilies Staticoideae and Plumbaginoideae (Plumbaginaceae): Evidence from plastid DNA sequences and morphology. Plant Syst. Evol. 229: 107-124.

Maas, P. J. M. & Westra, L. Y. Th. 2005. Plumbaginaceae. Neotropical Plant Families. 3rd ed., pp. 132-133. A.R.G. Gantner Verlag K.G., Ruggell.

Stevens, P. F. (2008). Angiosperm Phylogeny Website. Version 9 onwards. http://www.mobot.org/MOBOT/research/APweb/.

Tebbitt, M. 2004. Plumbaginaceae, pp. 300-302. In: Smith, N., Mori, S. A., Henderson, A., Stevenson, D. W. and Heald, S. V. (eds.). Flowering Plants of the Neotropics. The New York Botanical Garden, Princeton University Press, Princeton.

Vargas, C.A. 2003. Plumbaginaceae. In: Steyermark, J.A., Berry, P.E., Yatskievych, K. and Holst, B.K. Flora of the Venezuelan Guayana. Volume 7, pp 740-1. Missouri Botanical Garden, St. Louis.

Watson, L. and M. J. Dallwitz (1992 onwards). The Families of Flowering Plants: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 14th December 2000.