Stachytarpheta longispicata (Pohl) S.Atkins

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 : 34-36

Stachytarpheta longispicata (Pohl) S.Atkins

Figs 6G–I , 7E–F , 8E–F , 11

Kew Bulletin 60: 229 ( Atkins 2005). – Melasanthus longespicatus Pohl , Plantarum Brasiliae Icones et Descriptiones 1: 77, tab. 61 ( Pohl 1827), basionym. – Stachytarpheta chamissonis Walp. , Synopsis Verbenacearum, Myoporinearum, Selaginearum, Stilbinearum, Globulariearum et Plantaginearum. Repertorium Botanices Systematicae 4: 10 ( Walpers 1845). nom. illeg. [superfluous name].

Material examined

Type BRAZIL – Goiás • “ Habitat in montosis arids, ad Serra de Cristaes [Serra dos Cristais] Capitaniae Goyas [Goiás] ”; 1818; J.B.E. Pohl s.n.; lectotype: W[ W0073831 ] web!, designated by Cardoso et al. (2020); isolectotypes: BR[ BR0000008026668 ] web!, W[ W0073832 ] web !.

Representative specimens

BRAZIL – Goiás • “ Cristalina ”; 21 Feb. 1992; R. Mello-Silva et al. 559; SPF • “ Cristalina ”; 4 Feb. 1987; J.R. Pirani et al. 1523; SPF • “ Cristalina ”; 4 Feb. 1987; J.R. Pirani et al. 1613; SPF • “ Cristalina , beira de estrada ”; 21 Apr. 2008; J.F.B. Pastore & J.B.A. Bringel 2581; HUEFS • “ Cristalina, BR-040, 2 km L de Cristalina ”; 13 Aug. 1980; G. Hatschbach et al. 43059; MBM • “ Cristalina , BR-251 ”; 22 Jan. 1997; G. Hatschbach et al. 66127; ESA, MBM, SPF • “ Cristalina, estrada para Salto do Arrojado ”; 22 Jan. 1997; G. Hatschbach et al. 66127; MBM • “ Cristalina , Linda Serra dos Topázios ”; 13 Jun. 2004; J.F.B. Pastore 1005; CEN • “ Cristalina ”; 10 Sep. 1998; V.C. Souza et al. 21465; ESA • “ Cristalina, RPPN Linda Serra dos Topázios ”; 15 Dec. 1996; C.E.B. Proença 1660; UB • “ Cristalina , Serra dos Cristais ”; 8 Mar. 1966; H.S. Irwin et al. 13774; NY, RB • “ Cristalina, Serra dos Cristais , 9 km by road S of Cristalina on road to Catalão ”; 4 Apr. 1973; W.R. Anderson 8104; NY • “ Cristalina, entrada para a RPPN Linda Serra dos Topazios ”; 11 Mar. 2020, P.H. Cardoso et al. 46; CESJ • “ Cristalina, RPPN Linda Serra dos Topazios ”; 12 Mar. 2020; P.H. Cardoso et al. 48; CESJ .

Description

Clump-forming shrubs 0.7–1.2 m tall, erect, branched or unbranched, stems cylindrical, strigose to tomentose-hirsutulous, xylopodium present. Leaves opposite, patent, sometimes conduplicate, sometimes with smaller leaves on the axils, petiolate; petioles 3.7‒14.22 mm long, strigose; blades 16.02–33.42 × 13.3–27.2 mm, ovate, subrhomboid or subrotund, thickly-chartaceous, slightly discolorous, base cuneate or attenuate, decurrent into petiole, apex acute, obtuse or rounded, margin entire near the base, crenateserrate towards the apex, revolute, abaxially foveolate, tomentose-hirsutulous, veins evident forming a reticulate network, adaxially strigose. Inflorescences 183.22–562.61 × 17.95–24.5 mm, pendulous at the apex, rachis visible, tomentose-hirsutulous; bracts 4.3–6.79 × 0.91–1.51 mm, light green, triangular or narrowly triangular, apex caudate, abaxially tomentose-hirsutulous. Flowers pedicellate, pedicel 0.92– 2.2 mm long, tomentose-hirsutulous; calyx tube narrow, widened at apex, 9.37‒13.42 × 3.64–6.17 mm, light green, externally tomentose-hirsutulous at base, becoming strigose at apex, 5-toothed; corolla salmon, tube 13.66‒17.88 cm long, externally with pedicellate glandular trichomes. Fruits 0.3‒0.55 cm 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 longispicata is endemic to the Serra dos Cristais region in the Cerrado domain of Goiás State ( Fig. 5 ). It forms small and locally restricted populations growing in campos limpos (grasslands) and campos sujos (shrubby grasslands). Found fertile from January to April, and in June, August, September, and December.

Proposed conservation status

Stachytarpheta longispicata is endemic to the Serra dos Cristais region, with an estimated EOO of 38.121 km 2 and AOO of 30 km 2. It is not found inside protected areas, and its populations are clearly under anthropic influence, especially due to soybean and Eucalyptus crops and livestock ( Ignácio 2014; Carvalho 2018). Furthermore, the municipality of Cristalina is the world’s greatest quartz reserve and Brazil’s largest gem commercial centre ( Martinelli & Moraes 2013). Thus, S. longispicata should be considered “Critically Endangered” (CR), based on the B2ab(i,ii,iii,iv) criteria, due to its EOO <100 km 2, fragmented distributions, number of known collections, and continuous decline in habitat quality ( IUCN 2022).

Notes

Atkins (2005) characterised Stachytarpheta longispicata subsp. longispicata as a clump-forming shrub up to 1 m tall, branched, with a xylopodium, petiolate leaves, with small leaves on the leaf axils, leafblades fan-shaped, 15–4 × 12–30 mm, apex obtuse to rounded, base truncate to cuneate, inflorescence 250–330 mm long, pendulous at apex, rachis visible between the flowers, bracts narrowly triangular, ca 6 mm long and densely covered with uniseriate hairs, calyx ca 12 mm long, and corolla ca 18 mm long, ranging from orange to red. Despite not being the taxon most commonly and historically associated with the name S. longispicata , it certainly matches the species originally described by Pohl (1827) from Serra dos Cristais ( 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 inflorescences, bracts, calyx and corolla. Atkins (2005) presents longer measurements for the leaves, which most likely represents the combined petiole and leaf-blade length. However, we presently provide the length of both structures independently. According to Atkins (2005), the leaves of S. longispicata subsp. longispicata are fanshaped with a truncate or cuneate base. All specimens studied by the author were also analysed by us, where we observed ovate, subrotund and subrhombic leaves, with a cuneate or attenuate base, which is in agreement with the protologue: “ folia subrhombea, indivisa, crenata , ciliata , apice rotundata, integerrima , base cuneiformia, angustata ” ( Pohl 1827).

Based on our morphometric analysis, plus qualitative data and distribution, it is possible to recognise Stachytarpheta longispicata subsp. longispicata exclusively at the species rank. Stachytarpheta longispicata is disjunct from the remaining pedicellate species of the genus, being restricted to the Serra dos Cristais, Goiás State. It is characterised by its ovate, subrhombic or subrotund leaves, 16.02–33.42 × 13.3–27.2 mm, flowers laxly arranged along the rachis, and calyx 9.37‒13.42 mm long, tomentosehirsutulous at base, becoming strigose towards the apex.

Despite Atkins (2005) citing this species as restricted to the Serra dos Cristais region, she provides a specimen list including collections from the municipality of Niquelândia. In the present study, these specimens from Niquelândia are recognised as Stachytarpheta longipedicellata due to their long pedicels and distribution in the same geographic area.

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. 11. Stachytarpheta longispicata (Pohl) S.Atkins. A. Habitat. B. Habit. C–D. Individuals showing details of the leaves and inflorescences, highlighting the short pedicels, bracts, calyxes, and corollas. Photos by Marcelo Trovó.

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.