Stachytarpheta brevibracteata (Moldenke) P.H.Cardoso, 2022

Cardoso, Pedro Henrique, Neto, Luiz Menini, Somavilla, Nádia Silvia & Trovó, Marcelo, 2022, A morphometric approach and recircumscription of the Stachytarpheta longispicata complex (Verbenaceae), European Journal of Taxonomy 833, pp. 12-45 : 25-30

Stachytarpheta brevibracteata (Moldenke) P.H.Cardoso comb. and stat. nov.

Figs 6A–C , 7A–B , 8A–B , 9

Stachytarpheta chamissonis var. brevibracteata Moldenke, Phytologia 45: 38 ( Moldenke 1980), basionym. – Stachytarpheta longispicata subsp. brevibracteata (Moldenke) S.Atkins, Kew Bulletin 60: 231 ( Atkins 2005).

Material examined

Type BRAZIL – Minas Gerais • Morro das Pedras, 25 km NE of Patrocínio; 28 Jan. 1970; H.S. Irwin et al. 25457; lectotype: NY [ NY00138063 ] web!, designated by Cardoso et al. (2020); isolectotypes: MO[ MO1254482 ] web!, UB web! .

Representative specimens BRAZIL – Minas Gerais • “ Bambuí, entre Bambuí e Patos de Minas ”; 11 Feb. 2012; J.F.B. Pastore et al. 4027; HUEFS • “ Delfinópolis ”; 7 Sep. 1998; V.C. Souza et al. 21233; ESA • “ Delfinópolis, estrada para casa branca ”; 10 Apr. 2002; R. Romero et al. 6255; RB • “ Delfinópolis, Fazenda Água da Serra ”; 10 Mar. 2003; R.A. Pacheco 483; HUFU • “ Delfinópolis, Condomínio de Pedra ”; 17 May 2003; R.L. Volpi 675; HUFU • “ Furnas ”; 16 Nov. 1977; N.D. da Cruz et al. 6212; MBM • “ São Roque de Minas ”; 21 Mar. 1998; P.T. Sano et al. 963; SPF • “ São Roque de Minas, Parque Nacional da Serra da Canastra ( PNSC), estrada para a Serra das Sete Voltas ”; 19 Mar. 1995; R. Romero et al. 2026; CESJ, HUFU • “PNSC, estrada São Roque para Sacramento a 2 km da portaria Sacramento ”; 14 Apr. 2017; F.R.G. Salimena & P.H. Nobre 3989; CESJ • “PNSC, estrada São Roque – Sacramento km 60 ”; 22 Feb. 1997; J.N. Nakajima et al. 2265; CESJ, HUFU • “PNSC, Guarita de Sacramento ”; 29 Jun. 1994; R. Romero & J.N. Nakajima 1086; CESJ, HUFU • “PNSC, Guarita de Sacramento ”; 17 Oct. 1997; J.N. Nakajima et al. 2883; CESJ, HUFU • “PNSC, Guarita de Sacramento ”; 14 Jul. 1995; J.N. Nakajima et al. 1180; CESJ, HUFU • “PNSC, guarita de Sacramento ”; 11 Jan. 1998; R. Romero et al. 4991; CESJ, HUFU • “PNSC, Sacramento, próximo do Morro da Guarita 1 ”; 23 Feb. 1994; J.N. Nakajima & R. Romero 180; CESJ, HUFU • “PNSC, 3 km da Guarita de Sacramento ”; 19 Aug. 1997; R. Romero et al. 4418; CESJ, HUFU • “PNSC, 5 km da Guarita de Sacramento ”; 19 Mar. 1995; R. Romero et al. 2035; CESJ, HUFU • “PNSC, próximo a nascente do Rio das Velhas ”; 22 Nov. 1996; R. Romero & J.N. Nakajima 3818; CESJ, HUFU • “PNSC, próximo à Guarita de Sacramento ”; 6 May 2021; P.H. Cardoso & W.P. Leite 65; CESJ • “PNSC, próximo à Guarita de Sacramento ”; 6 May 2021; P.H. Cardoso & W.P. Leite 66; CESJ. – São Paulo • “ Pedregulho ”; 24 May 2003; D. Sasaki 534; SPF.

Description

Shrubs 0.8–2 m tall, erect, much-branched, stems cylindrical, tomentose, xylopodium present. Leaves opposite, patent to suberect, not conduplicate, sometimes with smaller leaves on the axils, deciduous at maturity, petiolate; petioles 3.57‒9.2 mm long, tomentose; blades 17.1–36.73 × 12.21–27.31 mm, ovate or subrotund, thickly-chartaceous, slightly discolorous, base cuneate or attenuate, decurrent into petiole, apex acute, obtuse or rounded, margin entire near the base, crenate-serrate towards the apex, revolute, abaxially not foveolate, tomentose, veins evident, adaxially strigillose. Inflorescences 64.22– 200.61 × 14.52–19.89 mm, pendulous or not at the apex, rachis visible, tomentose; bracts 3.31–5.13 × 0.68–1.07 mm, light green, linear-triangular, apex acute or acuminate, abaxially tomentose. Flowers pedicellate, pedicel 1.21–2.23 cm long, tomentose; calyx tube narrow throughout, not widened at the apex, 9.01‒13.03 × 1.98–2.9 mm, light green, externally tomentose from base to apex, 5-toothed; corolla dark red, tube 13.43‒21.31 mm long, externally with pedicellate glandular trichomes. Fruits 0.41‒0.58 mm long, castaneous, external surface reticulate, with thin and flat commissure, apex rounded with short stylopodium, prominent attachment scar, separating into two cluses, covered by the persistent calyx.

Distribution, habitat and phenology

Stachytarpheta brevibracteata is endemic to the Cerrado of the states of Minas Gerais and São Paulo ( Fig. 5 ). It is found growing in campos rupestres, campos limpos (grasslands), and campos sujos (shrubby grasslands), forming dense but fragmented populations. Found fertile throughout the year, except in December.

Proposed conservation status

Stachytarpheta brevibracteata has an EOO of 7 507.461 km 2 and an AOO of 32 km 2. Despite occurring inside a protected area, the Parque Nacional da Serra da Canastra, its distribution is mostly restricted to roadsides. It is subjected to the increase of unorderly tourist activity, the suppression of native vegetation by invasive species, and mostly by illegal fires ( IBAMA 2005). Therefore, S. brevibracteata should be considered “Endangered” (EN), based on criteria B2ab(i,ii,iii,iv) ( IUCN 2022), due to its AOO <500 km 2, fragmented populations, and a continuous decline of habitat quality.

Notes

Atkins (2005) described S. longispicata subsp. brevibracteata as subshrubs up to 1 m tall, branched, leaves ovate or subrotund, blades 12–25 × 5–12 mm, base attenuate, inflorescence 70–80 mm long, bracts linear and up to 3 mm long, calyx up to 12 mm long, covered by short hairs, and corolla dark red. The subspecies was established based solely on the type specimen and characterised by its short leaves and inflorescences ( Atkins 2005). When comparing our current circumscription with the one proposed by Atkins (2005), it is possible to observe differences regarding plant stature, leaf-blade size, and length of the inflorescence, bract, calyx and corolla. Atkins (2005) provides smaller measurements for leaves’ length and width. However, this is most likely associated with smaller axillary leaves, which are only analysed as qualitative characters in the present study.

Based on our morphometric analysis, plus qualitative data and distribution, Stachytarpheta longispicata subsp. brevibracteata is recognised by us at the species rank. Therefore, S. brevibracteata differs from the remaining species of Stachytarpheta with pedicellate flowers due to its branches, abaxial surface of the leaves, rachis, bracts and calyx tomentose, adaxial surface of the leaves strigillose, and narrow calyx (not enlarged towards the apex, equal or narrower than 2.9 mm width).

Figures

Fig. 6. Comparison between the main characteristics of the species used in the identification key (photos taken under the stereo microscope). A, D, G, J, M. Adaxial indumentum of the leaf-blade. B, E, J, K, N. Abaxial indumentum of the leaf-blade. C, F, I, L, O. Indumentum of the rachis, bracts, pedicel, and calyx. A–C. Stachytarpheta brevibracteata (Moldenke) P.H.Cardoso (P.H. Cardoso & W.P. Leite 66). D–F. S. longipedicellata (Moldenke) P.H.Cardoso (P.H. Cardoso et al. 59); G–I. S. longispicata (Pohl) S.Atkins (P.H. Cardoso et al. 48). J–L. S. minasensis (S.Atkins) P.H.Cardoso (F.R.G. Salimena & P.H. Nobre 459). M–O. S. ratteri (S.Atkins) P.H.Cardoso (P.H. Cardoso et al. 51).

Fig. 7. Comparison between the pubescence of the leaves of the species (photos taken under electron microscope). A, C, G, E, I. Adaxial surface. B, D, F, H, J. Abaxial surface. A–B. Stachytarpheta brevibracteata (Moldenke) P.H.Cardoso (P.H. Cardoso & W.P. Leite 66). C–D. S. longipedicellata (Moldenke) P.H.Cardoso (P.H. Cardoso et al. 59). E–F. S. longispicata (Pohl) S.Atkins (P.H. Cardoso et al. 48). G–H. S. minasensis (S.Atkins) P.H.Cardoso (F.R.G. Salimena & P.H. Nobre 459). I–J. S. ratteri (S.Atkins) P.H.Cardoso (P.H. Cardoso et al. 51).

Fig. 8. Comparison between the pubescence of the calyx of the species (photos taken under electron microscope). A, C, G, E, I. The most basal part. B, D, F, H, J. The most apical part. A–B. Stachytarpheta brevibracteata (Moldenke) P.H.Cardoso (P.H. Cardoso & W.P. Leite 66). C–D. S. longipedicellata (Moldenke) P.H.Cardoso (P.H. Cardoso et al. 59). E–F. S. longispicata (Pohl) S.Atkins (P.H. Cardoso et al. 48). G–H. S. minasensis (S.Atkins) P.H.Cardoso (F.R.G. Salimena & P.H. Nobre 459). I–J. S. ratteri (S.Atkins) P.H.Cardoso (P.H. Cardoso et al. 51).

Fig. 9. Stachytarpheta brevibracteata (Moldenke) P.H.Cardoso comb. and stat. nov. A. Habitat. B. Habit. C–D. Individuals showing details of the leaves and inflorescences, highlighting the short pedicels, bracts, calyxes and corollas. Photos by Pedro Henrique Cardoso (A–B) and Pedro Henrique Nobre (C).

Fig. 5. Distribution map of the five species recognised in the Stachytarpheta longispicata complex in the present study. The triangles represent localities sampled during fieldwork for the morphometric analysis.