Oocephalus tenuithyrsus Harley

This species is accepted, and its native range is Brazil (Bahia).


Harley, R.M. 2014. Four new taxa of Oocephalus (Hyptidinae: Lamiaceae) from Bahia, Brazil. Kew Bulletin 69: 9539. DOI https://doi.org/10.1007/s12225-014-9539-4

Although with a much restricted range, it is not infrequent in the area, as the number of collections cited will indicate. However the localities where it occurs are often anthropogenic, close to cultivation and where its survival is always precarious. It is here categorised as Endangered, with Extent of Occurrence 530.815 km sq. and Area of Occupancy 52 km sq. (IUCN 2001).
South America: NE Brazil. Bahia, Chapada Diamantina. Almost entirely restricted to the Município of Abaira, in the montane zone, with one record just over the border in the Município of Rio de Contas.
This species occurs almost exclusively in “carrasco” vegetation in the Município of Abaira, at the northern end of the Chapada Diamantina, Bahia State, where it is fairly frequent at middle altitudes, between 900 – 1160 m. The term “carrasco”, as used in this region, is a dry, open scrub, with low woodland, probably anthropogenic in origin and apparently a transition between Caatinga and Cerrado vegetation.
Morphology General Habit
Herb or subshrub, viscous, 1 – 1.6 m high, usually well-branched with slender, stems and leaves 2 – 4 mm diam., quadrangular above, rather densely hairy with slender, spreading gland-tipped hairs; cauline leaves with lamina 2.7 – 3.5 × 1.5 –2.2 cm, membranous, slightly discolorous, ovate-triangular with apex acute and base cordate to rounded or truncate, margin serrate, adaxial surface darker green with scattered, often short, broad-based hairs and with numerous sessile glands, abaxial surface usually more densely villous especially on the veins, hairs rather slender, often gland-tipped and with many sessile and some smaller stipitate glands, petiole 0.9 – 1.8 cm long, slender, rather densely hairy with spreading, villous, usually gland-tipped hairs
Morphology Reproductive morphology Flowers
Flowers with pedicels <1 mm long, calyx at anthesis 3.0 – 3.5 (– 5) mm long, tube 1.5 – 1.75 mm long, ±cylindrical, widening slightly towards throat, externally hairy with slender, spreading, often gland-tipped hairs, internally glabrous, veins slender, lobes c. 1.5 mm long, subequal, narrowly subulate, long-ciliate, with sinuses between lobes long-ciliate with dense whitish hairs, fruiting calyx cylindrical to weakly ellipsoid, 5.0 – 5.5 mm long, tube c. 3.5 mm long, lobes 1.4 mm long, rigid, weakly spreading; corolla with pale tube and posterior lobes vinaceous, anterior lip coral (orange-pink),2 tube c. 4.5 mm long, narrowly cylindrical, lobes externally pilose, stamens wth filaments hairy, gynoecium glabrous, stylopodium absent, stigma-lobes short
Morphology Reproductive morphology Fruits
Nutlets 1.0 – 0.6 mm, ellipsoid-oblong, apex rounded, dark brown, smooth, matte, glabrous, abscission scar pale, not mucilaginous when wet
Morphology Reproductive morphology Inflorescences
Inflorescence an elongate, terminal, usually much branched, interrupted, spiciformthyrse, 10 – 25 cm long, axis with indumentum as on stems, and consisting of pedunculate cymules, from the axis of leaf-like bracts, which decrease in size towards apex of inflorescence, peduncles slender, (2 –) 4 – 16 (– 25) mm long; cymules 12 – 15-flowered, 5 – 10 mm diam., with an involucre of bracteoles, the outer 4.5 – 6 × 1 – 2 mm, elliptic-lanceolate, pale green, weakly concave on adaxial surface and closely investing the immature cymules, but soon becoming separate, with margin entire or rarely slightly toothed, with rather few, slender, ascending, indistinct veins, adaxial surface glabrous, abaxial surface hairy, with long, slender, sometimes gland-tipped hairs, becoming paleaceous

From the Latin, meaning “slender thyrse”, in reference to the form of inflorescence.

Although morphologically very distinct, the new species could perhaps be mistaken for the widespread and extremely variable Cantinoamutabilis (Rich.) Briq. This latter species differs in its more robust habit, with non-viscous stems, leaves ovate to ovate-rhomboid, with often cuneate bases; cymules with the outer involucral bracteoles longer, 3.5 – 4 mm, not distinctly concave and with a distinct network of prominent veins, at least when dry (veins absent or indistinct in Oocephalustenuithyrsus), and the shorter calyx lobes, 0.5 – 0.7 mm, with the lobes in O. tenuithyrsus c. 1.4 mm long.

Herb related to Oocephalusoppositiflorus (=Hyptisglomerata Mart. ex Benth.), but differing in the more slender habit, with viscous, not usually purple-tinged stems. Leaves with petiole 9 – 18 mm long, slender, not with leaves sessile or petiole 1 – 6 mm long as in O. oppositiflorus, lamina ovate-cordate to ovate-triangular with base rounded to truncate, with apex acute to weakly acuminate, not ovate to ovate-oblong with base rounded to truncate, and apex obtuse to acute. Cymules with outer bracteoles 1 – 2 mm wide, as opposed to 2.5 – 4 mm wide in O. oppositiflorus and with corolla tube short, 4.5 mm long, and scarcely over-topping the calyx, as opposed to 5.7 – 6 mm long, distinctly overtopping the calyx in O. oppositiflorus.

Flowering Jan. −April; fruiting Feb. −July.

Type: Brazil. Bahia, Município de Abaira: Garimpo do Engenho, 13°18'S, 41°49'W, 1000 m, carrasco com solo arenoso, com rochas, 3 March 1994, Ganev 3032 (holotype: HUEFS!, isotype K!).

Native to:

Brazil Northeast

Oocephalus tenuithyrsus Harley appears in other Kew resources:

First published in Kew Bull. 69(4)-9539: 5 (2014)

Accepted by

  • Govaerts, R., Nic Lughadha, E., Black, N., Turner, R. & Paton, A. (2021). The World Checklist of Vascular Plants, a continuously updated resource for exploring global plant diversity. https://doi.org/10.1038/s41597-021-00997-6 Scientific Data 8: 215.

  • Kew Backbone Distributions

    The International Plant Names Index and World Checklist of Selected Plant Families 2022. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

  • Kew Bulletin

    Kew Bulletin

  • Kew Names and Taxonomic Backbone

    The International Plant Names Index and World Checklist of Selected Plant Families 2022. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0