Lippia horridula (Epling) Salimena, Múlgura & Harley 2012

Salimena, Fátima Regina G., Múlgura, Maria Ema & Harley, Raymond, 2012, A new combination in Verbenaceae and a new synonym in Lamiaceae from Brazil, Phytotaxa 68 (1), pp. 52-54 : 52-53

Lippia horridula (Epling) Salimena, Múlgura & Harley , comb. nov.

Basionym : Eriope horridula Epling (1936: 191) . Type :— BRAZIL. Goyaz: Prope Porto Real, 4 December 1828, W. J . Burchell 8426-5 (holotype K!) .

Subshrub ca. 20 cm tall, with well-developed woody xylopodium, stems quadrangular, 0.7−20 cm long, with conspicuous nodes, hirsute when young, with stalked glandular trichomes, glabrescent at maturity. Leaves opposite, subsessile, petioles ca. 1.0 mm long, glabrous, lamina 2.0−5.0 × 0.4−0.8 cm, narrowly elliptic, with base and apex acute, margin serrate, ciliate, glabrous on both surfaces or sparsely strigose and with sessile glandular trichomes, venation craspedodromous. Inflorescence in a frondose, homothetic pleiobotrys, partial inflorescence spiciform, peduncle 0.7–1.5 cm long, densely glandular with stalked glandular trichomes and simple, non-glandular trichomes, bracts 5.0 × 2.0 mm, elliptic, adaxial surface glandular-hispid with stalked glandular trichomes, apex reddish; calyx from 1.5 mm long, cylindrical, bi-lobed, densely hispid, trichomes non-glandular, 3.0 mm long; corolla pinkish with tube 5.0 × 1.0 mm, hirsute with short, simple trichomes, lobes ca. 4.0 mm long. Fruit unknown.

Distribution and habitat:— Lippia horridula is a species endemic to the Brazilian states of Goiás, Tocantins and the Distrito Federal, occurring in the “cerrado” and the “campo rupestre”, above 1000 m altitude, resprouting after the areas have been burnt.

Selected specimens examined:— BRAZIL. Distrito Federal: Área do Cristo Redentor , 28 August 1990, P . S . Câmara & M . S . Câmara 23 ( SI); Estação Florestal Cabeça de Veado, July1985, Equipe do Jardim Botânico de Brasília 448 ( HEPH); Reserva Ecológica do IBGE , 17 October 1994, M . L . Fonseca & F . C . A. Oliveira 138 ( SI) . Goiás: Corumbá, Pirineus , 28 July 1952, A . Macedo 3694 ( SI); Prope Cavalcante , 30 September 1829, W . J . Burchell 7921 ( K); Prope Canga , 5 November 1828, W . J . Burchell 8291 ( K) . Tocantins: Prope Porto Nacional ( Porto Real ), 24 March 1829, W . J . Burchell 8746-2 ( K) .

Observations:— Lippia horridula is similar in habit to Lippia grandiflora Mart. & Schauer ex Schauer (1847: 591) , from Southern Brazil, with the development of a woody xylopodium and with a similar flower colour, but differs in the form of the leaves, which in L. horridula are narrowly elliptic, with the margins serrate and ciliate at the apices of the teeth and with the calyces densely hispid, while in L. grandiflora the leaves are ovate to rotund with margin crenate and calyx with strigose indumentum.

A study of the type collections of Lippia adpres sa Hayek (1906: 87) resulted in its recognition as a new synonym of Hyptis obtecta Bentham (1848: 99) .

Hyptis obtecta Bentham (1848: 99) . Mesosphaerum obtectum (Benth.) Kuntze (1891: 526) . Lectotype (designated by Epling 1936: 289):— BRAZIL. Goyaz: without locality, J. B. E. Pohl 1654 (lectotype K!, isolectotype BR!)

Lippia adpressa Hayek (1906: 87) , syn. nov. Type : — BRAZIL. Goyaz: without locality, G. Gardner 3933 (holotype W!; isotypes K!, OXF!, MANCH!, NY!, P!, SI! Photograph Series FM 34328 , SI!)

In the protologue of Hyptis obtecta, Bentham (1848) cited various herbarium collections, including Gardner 3933, which was chosen by Hayek as the holotype of his species Lippia adpressa Hayek (1906: 87) . Hayek, in the original description, cited Gardner 2933 as the type collection, but this appears to be a typographic error for “3933” as is plainly indicated on the holotype deposited in W. A study of the specimens of this collection confirms its identity as Hyptis obtecta Bentham (1848: 99) , Lamiaceae , as originally proposed by Bentham, and not as a member of the Verbenaceae . In a recent paper, Harley & Pastore (2012) divided Hyptis into a number of genera, based mainly on molecular evidence. However, the section to which Hyptis obtecta belongs, sect. Eriosphaeria Bentham (1833: 88) remains in the genus Hyptis sensu stricto.

Hyptis obtecta is a very striking species, occurring in the “cerrado” and the “campo rupestre” of Goiás and characterized by its small, sessile leaves, which are cordate and adpressed to the stem, and covered by a dense indumentum of appressed grey hairs.

A superficial similarity between species of the genus Hyptis (Lamiaceae) with species of Lippia (Verbenaceae) has resulted in a confused taxonomy with the recent and necessary creation of a number of synonyms ( Harley & Salimena 1998), such as Lippia cipoensis Moldenke (1959: 446) as a synonym of Hyptis passerina Mart. ex Bentham (1833: 89) and Lippia grisea Moldenke (1970: 242) a synonym of Hyptis saxatilis A.St. -Hil. ex Bentham (1833: 90).