Stachytarpheta tomentosa P.H. Cardoso & Salimena, 2019

Cardoso, Pedro Henrique, Neto, Luiz Menini & Salimena, Fátima Regina Gonçalves, 2019, A new species of Stachytarpheta (Verbenaceae) from an inselberg of Espírito Santo state, Brazil, Phytotaxa 400 (5), pp. 273-278 : 274-277

Stachytarpheta tomentosa P.H. Cardoso & Salimena sp. nov., Fig. 1 A–G .

Type: — BRAZIL. Espírito Santo: Itarana, Alto Várzea Alegre, Pedra da Onça, 19°53’45”S and 40°48’46”W, 892 m, 19 April 2013 (fl. and fr.), R. C. Forzza et al. 7530 (holotype CESJ, isotype RB).

Diagnosis: —The new species resembles Stachytarpheta gesnerioides , but differs by having tomentose branches; lanceolate leaves with acute leaf apex, strigose adaxial surface, tomentose abaxial surface; tomentose bracts; calyx 4-toothed with adaxial sinus; and blue corolla with white throat. Stachytarpheta tomentosa also resembles S. sprucei Moldenke (1940: 474) , but can be distinguished by winged branches, tomentose in all sides; lanceolate leaves, tomentose abaxial surface; tomentose bracts; and calyx externally hirsute along the ribs.

Shrub 1–2.5 m height, branched, erect branches, tetragonal, winged, tomentose, internodes 1.2–3 cm long. Leaves decussate, petiolate, petiole 4–6 mm long, tomentose; blade 4.8 ‒ 8.3 × 1.3 ‒ 2.5 cm, lanceolate, cartaceous, apex acute, base atenuate, decurrent into petiole, margin entire near to base, crenate towards the apex, ciliate, adaxial surface strigose, veins impressed, abaxial surface tomentose, nectaries near the petiole, midvein and secondary veins prominent. Inflorescence 18 ‒ 25.5 cm long, 1.2 ‒ 1.5 cm wide, compact, rachis not visible, tomentose, flowers sessile; bracts 0.8–1.1 cm long, green, membranaceous, becoming rigid after fruiting, narrowly triangular, apex aristate, abaxially tomentose, margin ciliate, persistent; calyx 1–1.3 cm long, green, tubular, erect, not embedded in the rachis, 4-toothed, unequal teeth, 1 adaxial sinus, externally hirsute along the ribs, puberulent between the ribs, 4 distinct nectaries; corolla blue with white throat, tube 2–2.2 cm long, cylindrical, externally with glandular pedicellate trichomes, 5-lobed, lobes 5–6 mm long, equal, fertile stamens 2, staminodes 2, pilose, included, inserted at the top of corolla tube, thecae divergent; ovary 2–3 mm long, bicarpellate, 2-loculate, 1 ovule per locule, style 2.3–2.4 cm long, filiform, stigma capitate. Fruit a schizocarp, 6–7 mm long, oblong, apex extended and flattened, style persistent, light-brown, external surface slightly reticulate, proeminent attachment scar, enclosed by the persistent calyx, splitting at maturity in two mericarps.

Additional specimens examined (paratypes): — BRAZIL: Espírito Santo: Pedra da Onça , 19°53’55,6”S and 40°48’56”W, 900 m, 16 Jan 2013, (fl.), L. Kollmann et al. 12593 ( MBML) ; Pedra da Onça , 1 Jun 2000, (fl. and fr.), L. Kollmann et al. 2983 ( CESJ, MBML) ; Pedra da Onça , 1 Jun 2000, fl. and fr. A. M. Amorim 3406 ( CEPEC, SPF) .

Distribution, habitat and phenology: — Stachytarpheta tomentosa is currently known only from the Pedra da Onça inselberg, in the municipality of Itarana, Espírito Santo state, at approximately 900 m. a.s.l. ( Figure 2 ). It was collected in flower in January, April and June and with flowers and fruits in April and June.

Conservation status: —Known from a single location, it is found outside a conservation unit. The Pedra da Onça is a private property surrounded by coffee and eucalyptus plantations. In addition, there is a little chapel on the top of the inselberg, open to visitors, which may represent a threat to the local biodiversity, as visitation causes trampling and also has been observed to bring invasive species into the area. The data provided on the herbarium label of the holotype specimen states that is a common species on this inselberg. However, the first author made an expedition to this area and did not find any specimens. Thus, based on IUCN criteria ( IUCN 2017), we assign the species as Critically Endangered (CR), AOO<10km 2, B2ab (ii, iii, iv, v).

Etymology: —The species epithet refers to the tomentose indumentum of the branches, and on the abaxial surface of the leaf blade and the bracts.

Discussion: — Stachytarpheta tomentosa may be included in the informal group “Gesnerioides ” proposed by Atkins (2005), because it has inflorescences up to ca. 55 cm long, 1.5 cm wide, calyx erect, not embedded in rachis, blue corolla, tube longer than 1.5 cm, lobes 4–6 mm long, stamens inserted in the superior portion of the corolla tube and fruit externally reticulated, with apex extended and flattened with short stylopodium. Although Atkins (2005) uses the number of the calyx teeth (five) important to recognize the group “Gesnerioides ”, this character is variable within the group, once both S. amplexicaulis Moldenke (1947: 320) and S. sprucei , placed in this group by Atkins (2005), present 4-toothed calyx. Moreover, from the thorough analysis of several collections it was possible to verify that the different stages of flower maturation show variable calyx morphology in the same individual. That is, the mature calyx exhibits 5-teeth, however can display only four in the pre-anthesis. Thus, the new species must be included in the group “Gesnerioides ”, and a note must be made to the effect that this group includes species with calyces with four or five teeth.

Among the seven species of the “Gesnerioides ” group, S. tomentosa resembles S. gesnerioides because of its tetragonal, winged branches; leaves with attenuated base, decurrent into petiole; inflorescence compact, rachis not visible and bracts narrowly triangular. S. gesnerioides present three varieties: S. gesnerioides var. gesnerioides characterized by leaf blade sparsely pubescent; S. gesnerioides var. glabra Atkins (2005: 202) that presents leaf blade glabrous and S. gesnerioides var. hirsuta Atkins (2005: 204) with leaf blade hirsute. The new species present adaxial surface of the leaf blade strigose and abaxial surface tomentose, an indumentum pattern different from the aforementioned infraspecific taxa of S. gesnerioides . Stachytarpheta tomentosa is also related to S. sprucei , a species distributed in the north of South America, in Venezuela, Guyana and Brazil (Roraima), because of the tetragonal branches; leaf with apex acute, attenuate base; bracts narrow triangular; calyx 4-toothed and corolla tube longer than 2 cm. However, the new species can be distinguished by the characters summarized in Table 1.

and S. sprucei .

Figures

FIGURE 1. A. Habit; B. Detail of the abaxial (left) and adaxial (right) leaf surfaces; C. Floral bract; D. Abaxial surface of the calyx; E. Adaxial surface of the calyx; F. Corolla; G. Fruit. (R.C. Forzza et al. 7530 (CESJ). Drawn by Ricardo Borges)

FIGURE 2. Geographic distribution of Stachytarpheta tomentosa and S. gesnerioides var. gesnerioides. The distribution of S. gesnerioides var. gesnerioides, a species predominantly found in the Cerrado, is shown only for Atlantic Forest for the purposes of this paper.