Lecantheae

Belongs within: Urticaceae.

The Lecantheae is a group within the Urticaceae, distinguished by the possession of a brush-like stigma. Though flowers are unisexual, female flowers retain the modified male organs as staminodes that function to eject the developing fruits upon maturity.

Lecantheae and/or Elatostemateae

Published 14 January 2013

The Elatostemateae are a tribe of plants in the Urticaceae, the family that includes the nettles. Elatostemateae are mostly distinguished from other members of the Urticaceae by their generally tripartite perianth in the female flowers and their brush-like stigmas (Friis 1993). There seems to be some conflict over the appropriate name to call this group: Conn & Hadiah (2009) argued for the use of Elatostemateae, but many authors had previously called this group the Lecantheae. The argument hinges purely on a question of priority a bit too tedious to examine here.

The question may or may not be moot, anyway. Recent phylogenetic analyses of the Urticaceae have generally agreed that the Elatostemateae can be divided between two clades, one including the genus Elatostema and the other the genera Lecanthus and Pilea. The two groups are morphologically as well as molecularly distinguishable: species of Pilea and Lecanthus generally have opposite leaves, but in Elatostema one of each leaf pair has been greatly reduced (or lost) so that the leaves appear alternate. However, it is currently uncertain whether these two groups together form an exclusive clade. In the analyses by Hadiah et al. (2008), trnL-F sequence data was consistent with a monophyletic Elatostemateae, but rbcL data placed the Lecanthus-Pilea group closer to the tribe Urticeae than to Elatostema. This is not inherently unreasonable: as members of the Urticeae also have brush-like stigmas like those of Elatostemateae, the main distinction between the two tribes is the plesiomorphic absence in the latter of the stinging hairs that characterise the Urticeae.

Whether monophyletic or not, the Elatostemateae are mostly a tropical and subtropical group. They are mostly herbs and subshrubs, with a smaller number of shrub species. The centre of diversity is in the Old World; only the genus Pilea is found in the Americas. Members of the Elatostema group may be either all included in a single genus or divided between genera Elatostema, Procris and Pellionia distinguished by inflorescence characters. Pilea, the largest genus in the group, includes species in both the Old and New Worlds, of which some are commonly succulent. The Hispaniolan species Pilea fairchildiana has developed a rosulate growth form, remarkably similar to members of genera in the unrelated family Crassulaceae, such as Aeonium and Sempervivum. Until very recently, this species was considered distinctive enough to be placed in a separate genus Sarcopilea; Jestrow et al. (2012) demonstrated its more nested position. Economic usages of Lecantheae species are few: the leaves of some Pilea species, such as the artillery plants* P. microphylla and P. melastomoides, have some limited use as aromatic herbs, while some species of the Elatostema group are apparently used in Indonesia as shampoo.

*The name ‘artillery plant’ apparently refers to the way in while the male flowers fire forth their pollen, which is supposed to resemble gunsmoke.

Systematics of Lecantheae

Characters (from Hadiah et al. 2003): Staminodes ejecting mature achenes; leaves opposite, anisophyllous to completely reduced; stipules intrapetiolar, fused; cystoliths uniformly linear.

<==Lecantheae [Procrideae]
    |--LecanthusYY22
    |--Elatostema Forster & Forster 1776HQC03, A61 [incl. E. subg. PellioniaHQC03]
    |    |  i. s.: E. dissectumDD73
    |    |         E. integrifoliumA78
    |    |         E. lineolatumDD73
    |    |         E. platyphyllumDD73
    |    |         E. rugosum Cunn. 1838A61
    |    |         E. sessileDD73
    |    |         E. surculosumDD73
    |    |--+--E. repensHQC03
    |    |  `--+--E. curtisiiHQC03
    |    |     `--ProcrisHQC03
    |    |          |--P. frutescensHQC03
    |    |          |--P. insularisHQC03
    |    |          `--P. wightianaDD73
    |    `--+--E. griffithianumHQC03
    |       |--E. (subg. Weddelia) parvumHQC03
    |       `--E. subg. EuelatostemaHQC03
    |            |--E. acuminatumHQC03
    |            `--+--E. subg. ElatostematoidesHQC03
    |               |    |--E. rostratumHQC03
    |               |    `--E. sesquifoliumHQC03
    |               `--+--+--E. strigosumHQC03
    |                  |  `--E. velutinicauleHQC03
    |                  `--+--E. pedunculosumHQC03
    |                     `--+--+--E. macrophyllumHQC03
    |                        |  `--E. nigrescensHQC03
    |                        `--+--E. reticulatumHQC03
    |                           `--E. stipitatumHQC03
    `--PileaHQC03
         |--P. baltenweckiiJ87
         |--P. bracteosaDD73
         |--P. cardiophyllaJ87
         |--P. cellulosaJ87
         |--P. cephalanthaJ87
         |--P. diandraJ87
         |--P. distantifoliaJ87
         |--P. domingensisJ87
         |--P. ellipticaD03
         |--P. formonensisJ87
         |--P. franquervilleanaJ87
         |--P. godetianaJ87
         |--P. hepaticaJ87
         |--P. lanceolataJ87
         |--P. lapidincolaJ87
         |--P. leptocardiaJ87
         |--P. microphyllaHQC03
         |--P. nummulariifoliaHQC03
         |--P. parietariaJ87
         |--P. propinquaJ87
         |--P. psilogyneJ87
         |--P. pumilaHQC03
         |--P. scriptaSS72
         |--P. serpyllaceaJ87
         |--P. smilacifoliaDD73
         |--P. stoloniferaJ87
         `--P. torbecianaJ87

*Type species of generic name indicated

References

[A61] Allan, H. H. 1961. Flora of New Zealand vol. 1. Indigenous Tracheophyta: Psilopsida, Lycopsida, Filicopsida, Gymnospermae, Dicotyledones. R. E. Owen, Government Printer: Wellington (New Zealand).

[A78] Ananthakrishnan, T. N. 1978. Thrips galls and gall thrips. Zoological Survey of India, Technical Monograph 1: 1–69, 26 pls.

Conn, B. J., & J. T. Hadiah. 2008. Nomenclature of tribes within the Urticaceae. Kew Bulletin 64: 349–352.

[DD73] Deb, D. B., & R. M. Dutta. 1973. Contribution to the flora of Tirap Frontier Division. Journal of the Bombay Natural History Society 69 (3): 547–573.

[D03] Dusén, P. 1903. The vegetation of western Patagonia. In: Scott, W. B. (ed.) Reports of the Princeton University Expeditions to Patagonia, 1896–1899 vol. 8. Botany pp. 1–34. The University: Princeton (New Jersey).

Friis, I. 1993. Urticaceae. In: Kubitzki, K., J. G. Rohwer & V. Bittrich (eds) The Families and Genera of Vascular Plants vol. 2. Flowering Plants. Dicotyledons. Magnoliid, hamamelid and caryophylliid families pp. 612–629. Springer.

Hadiah, J. T., B. J. Conn & C. J. Quinn. 2008. Infra-familial phylogeny of Urticaceae, using chloroplast sequence data. Australian Systematic Botany 21: 375–385.

[HQC03] Hadiah, J. T., C. J. Quinn & B. J. Conn. 2003. Phylogeny of Elatostema (Urticaceae) using chloroplast DNA data. Telopea 10 (1): 235–246.

Jestrow, B., J. J. Valdés, F. Jiménez Rodríguez & J. Francisco-Ortega. 2012. Phylogenetic placement of the Dominican Republic endemic genus Sarcopilea (Urticaceae). Taxon 61 (3): 592–600.

[J87] Judd, W. S. 1987. Floristic study of Morne La Visite and Pic Macaya National Parks, Haiti. Bulletin of the Florida State Museum—Biological Sciences 32 (1): 1–136.

[SS72] Singh, V., & H. Singh. 1972. A contribution to the flora of Gangolihat block in Pithoragarh District. Journal of the Bombay Natural History Society 69 (2): 352–368.

[YY22] Yampolsky, C., & H. Yampolsky. 1922. Distribution of sex forms in the phanerogamic flora. Bibliotheca Genetica 3: 1–62.