Hyptis piranii Harley (1992: 575)

Soares, Arthur De Souza, Harley, Raymond Mervyn, Pastore, José Floriano Barêa & Jardim, Jomar Gomes, 2022, There and back again: Oocephalus piranii is better treated as Hyptis (Hyptidinae, Lamiaceae), Phytotaxa 532 (2), pp. 183-187 : 184-186

Hyptis piranii Harley (1992: 575)

≡ Oocephalus piranii (Harley) Harley & J.F.B.Pastore (2012: 35) . ( Figure 1 ).

Type:— BRAZIL. Minas Gerais, Grão-Mogol: Descida do Morro Papo da Ema , para Jambeiro , Pirani, J.R. et al. CFCR 13069 (holotype: SPF00069476!; isotypes: K000488440!, MBM243817!, NY00857813!) .

Non-viscid shrub, ca. 1.5 m tall, branched on the upper portion, radicular system not observed. Branches velutinous, densely covered with short, white and appressed hairs. Leaves opposite, decussate, slightly imbricate in the upper portion, petiolate, the petiole 2.7–5.0 mm long, leaf blade 0.7–1.8 × 0.4–0.9 cm, flabelliform to obovate or obdeltate, margin entire, becoming crenate towards apex, coriaceous, craspedodromous venation, prominent below, adaxial surface green, tomentose, densely covered with short white hairs; abaxial surface paler, indumentum as on the adaxial surface, apex rounded to rarely retuse, base cuneate. Inflorescence thyrsoid, composed of pedunculate appressed capitula, hidden in the axil of leaf-like bracts, peduncle 2.0– 2.5 mm long, capitula hemispherical, 0.9–1.2 × 0.7–1.2 cm long, 4–3-flowered, bracteoles forming an involucre at the base of the cyme, green, 2.5 × 1.0 mm, oblong to elliptic, concave, outer surface tomentose, densely covered with short white hairs, inner surface glabrous. Flower sessile; calyx at anthesis pale green, 5.3–5.5 × 2.0– 2.2 mm long, tubular, membranous, outer surface tomentose, densely covered with short white hairs and long hairs concentrated at the base, glabrous within except for the short white hairs between the lobes, tube 4.0 mm long, lobes 1.3–1.5 mm long, deltate, membranous, tomentose, densely covered with white short hairs; fruiting calyx pale brown, 4.8–5.1 mm long, tubular, slightly coriaceous, outer surface tomentose, densely covered with short white hairs, glabrous within except for a ring of short white hairs between the lobe, tube 3.8–4.0 mm long, lobes 1.0– 1.1 mm long, triangular, slightly coriaceous, densely covered with white short hairs; corolla lilac, tube 8.0– 8.2 mm long, 1.1–1.2 mm diam. near the base, 1.8–2.0 mm diam. near the throat, outer surface slightly tomentose, covered with short white hairs, glabrous within except for a ring of white short hairs near the base, lobes 1.0 mm long, apex rounded; stamens with filaments glabrous at distal portion, densely hairy at the base, anthers brown; gynoecium glabrous, stigma lobes shortly bilobed, style ca. 9.5 mm long, stylopodium present, overtopping the ovary by ca 1.0 mm. Nutlets brown, 1.1–2.0 × 1.0 mm, ovate, glabrous, sometimes apically toothed, not mucilaginous when wet.

Specimens examined:— BRAZIL. Minas Gerais, Município: Botumirim, contrafortes orientais da Serra da Canastra, trilha do Cruzeiro a partir do posto de gasolina até o alto da serra nas nascentes do córrego São Domingos. 29 September. 1997, Mello-Silva, R. et al. 1472 (HUEFS, K, SPF); Município: Grão Mogol, Descida do Morro do Papo da Ema, 15 June 1990, Pirani, J.R. et al. CFCR 13069 (HUEFS, K, MBM, MO, NY, SP, SPF); Jambeiro, a 7 km de Grão Mogol, 5 Sep. 1987, Zappi, D.C. et al. CFCR 8542 (K, SPF); Trilha dos Garimpeiros, 14 June 1990, Hatschbach, G. et al. 54301 (FLOR, K, MBM, MO, NY); Município: Itacambira, Estrada Juramento-Itacambira, ca. 9 km de Itacambira, 3 February 2018, Antar, G.M. et al. 2068 (HUEFS, SPF); ibid, Antar, G.M. et al. 2078 (SPF).

Morphological evidence of Hyptis piranii generic position— Hyptis piranii was described by Harley (1992), based on the material collected by Pirani et al. (CFCR 13069) in the southern portion of Espinhaço Range, Minas Gerais state. Due the tomentose indumentum, composed of short and appressed white hairs, giving a silvery tonality, and the inflorescence born in the axil of leaf-like bracts, at first sight, H. piranii resembles two other species, Oocephalus argyrophyllus ( Harley 1985: 614) Harley & Pastore (2012: 33) (≡ H. argyrophylla Harley ) and O. halimifolius (Martius ex Bentham 1883: 94) Harley & Pastore (2012: 34) (≡ H. halimifolia Mart. ex Benth. ), both occurring in the Northern portion of the Espinhaço Range, Bahia state. These combined features led Harley (1992) to accommodate H. piranii in sect. Polydesmia subsect. Oocephalus , along with five other species, including the two mentioned above. With the taxonomic combination proposed by Harley & Pastore (2012), H. piranii was placed in Oocephalus , as O. piranii . However, the inflorescence morphology, which is the main feature to distinguish Hyptidinae genera, in H. piranii is quite different from the species belonging to Oocephalus . While Oocephalus members have a thyrsoid structure composed of pedunculate or sessile, ± ovoid, bracteolate cluster of congested cyme and flowers with a long corolla tube and short lobes, these are never blotched or marked with any lines, Hyptis species are characterized by having cymose hemispherical capitula, or often spherical, with an involucre of a number of bracteoles, sometimes forming complex synflorescences, flowers usually small with posterior lobes often blotched or marked. Additionally, morphological analysis of H. piranii revealed the presence of a stylopodium ( Figure 1B ), which is the basal part of the style that persists jointed to the ovary apex after the fall of the distal portion, a feature absent in Oocephalus species ( Harley 2014; Soares et al. 2021). This morphological character has an important role in the taxonomy of Hyptidinae , as pointed out by Harley (1988), who used it as a diagnostic character for members of Eriope Humboldt & Bonpland ex Bentham (1833: 142) , Hypenia (Martius ex Bentham 1833: 136) Harley (1988: 91) , Hyptidendron Harley (1986: 90) and some sections of Hyptis .

Sectional classification— Of the currently recognized sections of Hyptis , sect. Apodotes Benth., sect. Eriosphaeria Benth., sect. Induratae Epling , sect. Pachyphyllae Harley and sect. Xylodontes Benth. possess a stylopodium. Members of sect. Apodotes has its flowers arranged in a hemispherical capitula, which could be sessile and forming a spike, as in Hyptis nudicaulis Bentham (1833: 79) , or pedunculate, and calyx with subulate or lanceolate lobes with a deep sinus between the two anterior ones. In sect. Xylodontes, the indumentum of the capitula is slightly hirsute, calyx lobes are also lanceolate or subulate, and the bracteoles are somewhat larger. Morphologically, Hyptis piranii does not matches with neither of these two sections. In the most recent Hyptidinae phylogeny ( Pastore et al. 2021), molecular data supports that sect. Pachyphyllae should revert to subsectional rank along with sect. Induratae within sect. Eriosphaeria, where H. piranii apparently belongs, corroborated by the anatomical results shown by Rudall (1980), that suggest a close relationship between the first two groups.

Species from sect. Eriosphaeria are herbs, shrubs or subshrubs densely covered with long or short hairs, flowers usually arranged in a hemispherical, short pedunculate capitulum with an involucre of narrowly lanceolate bracteoles and the gynoecium with a well-developed stylopodium ( Harley 1986; Harley & Antar 2019). Although H. piranii has characters that place it in sect. Eriosphaeria, it still unclear into which subsection it would be best accommodated this species, even though it shares some similar characters with the species of subsect. Passerinae, such as leaf indumentum slender and appressed, bracteoles oblong, densely covered with short hairs and usually smaller than the calyx ( Epling 1949; Harley & Pastore 2010). Despite this, the inflorescence of H. piranii is quite different from those species of subsect. Passerinae [e.g. Hyptis gardneri Briquet (1898: 230) and Hyptis kramerioides Harley & Pastore (2010: 59) ], which have inflorescence composed of pedunculate or sessile, subspherical capitulum surrounded by an involucre of bracteoles. In H. piranii , the inflorescence anomalous, being reduced to three flowers, appressed dorsiventrally and hidden by the leaf-like bracts and bracteoles not forming an involucre. A phylogenetic approach focusing on Hyptis sect. Eriosphaeria is needed and could indicate the right position of this species within it.

Figures

FIGURE 1. Hyptis piranii: A: Three-flowered inflorescence; B: Detail of stylopodium overtopping the ovary; C: Inflorescence hidden in the axil of leaf-like bract on a flowering branch. Images:A and B taken from Zappi et al. CFCR 8542; C: Guilherme Antar.