Psyllocarpus itakangapyra Sobrado, J. A. M. Carmo & R. M. Salas 2022, sp. nov.
Creators: name: Sobrado, Sandra V.
name: do Carmo, João A. M.
name: Simões, André O.
name: Salas, Roberto M.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Gentianales
Rubiaceae
Psyllocarpus
Psyllocarpus itakangapyra

description: Psyllocarpus itakangapyra Sobrado, J.A.M.Carmo & R.M.Salas sp. nov.
urn:lsid:ipni.org:names:77296003-1
Figs 1, 3A–I, 4A–H, 5A–D, 6A–F, 7
Diagnosis
Psyllocarpus itakangapyra sp. nov. is similar to P. laricoides Mart. & Zucc., but differs by the leaves 1.45–3.4 mm long (vs (4)5–16(21) mm long in P. laricoides), flowering branches determinate (vs indeterminate), inflorescences in terminal glomerules, rarely with axillary inflorescences in 1-flowered cymes (vs axillary inflorescences in 1-flowered cymes), corolla tube 1.78–2.08 mm long (vs 2.9–6.7 mm long), calyx tube absent to vestigial (vs present), and seeds broadly obovate in outline (vs elliptic to broadly elliptic in outline).
Etymology
The specific epithet refers to the municipality of Itacambira, in the state of Minas Gerais, where the species is found. ʻ Itakangapyra ʼ means ʻstone with a pointed headʼ and derives from the ancient Tupi, an extinct Tupi language that was spoken by the Tupi tribes that inhabited most of the Brazilian coast in the 16 th century.
Material examined
Type
BRAZIL • Minas Gerais, Itacambira, Serra Resplandescente, “no caminho para a torre de Itacambira” [on the way to the Itacambira tower]; 17°04′56″ S, 43°18′20″ W; 1304 m a.s.l.; 28 Oct. 2009; Viana, Cardoso, Hattori & Salas 4415; holotype: BHCB[134173]!; isotype: CTES!.
Paratypes BRAZIL – Minas Gerais • Itacambira, MG 308, km 98; 17°04′58″ S, 43°18′35″ W; 17 Jan. 2015; Carmo & Scatigna 297; CTES!, UEC[207471]! • Itacambira, MG 308, km 99; 17°04′59″ S, 43°18′35″ W; 17 Jan. 2015; Carmo & Scatigna 298; CTES!, UEC[208470]!.
Description
Subshrubs, 0.4–2 m tall, sympodial. Stems branched, erect, internodes 1.25–8.11 mm long, 1.68–3.11 mm wide at the apex, tetragonal to subtetragonal and scabridous, 0.26–1.6 mm wide at the base, subterete and glabrous, bark peeling from older internodes, foliar scars conspicuous. Stipular sheaths 0.48–0.94(1.29) mm long, scabridous to glabrous, 3–5-fimbriate on each side of the stem, fimbriae 0.17–0.68 mm long, linear to narrowly triangular, colleter tipped, margin scabridous. Leaves opposite, with axillary brachyblasts forming fascicles, leaf blades 1.45–3.4 × 0.2–0.45 mm, slightly reflexed, decussate, apparently fleshy, sessile, linear to terete, apex obtuse, glabrous. Flowering branches determinate, 1–4.72 cm long, unbranched or with 3–5 branches per axis, inflorescences in terminal glomerules, 6–10-flowered, 3.4– 5.93 mm wide, rarely a 2–3-flowered cyme axillary, peduncle 2.07–9.28 mm long, external bracts 2, 1.43–2.24 × 0.18–1 mm, patent, linear to terete, apex obtuse, glabrous. Flowers sessile, homostylous; hypanthium 1.03–1.47 × 0.56–1.29 mm, obconic, glabrous; calyx tube absent to vestigial, 2-lobate, 3–5 fimbriae along the calyx rim between the lobes, 0.12–1.61 mm long, colleter tipped, calyx lobes (0.7)0.91–1.14 × 0.22–0.61 mm, narrowly triangular to linear, spatulate, glabrous; corolla 3–3.58 mm long, infundibuliform, lower half of the tube purple, the upper half and lobes light blue, corolla tube 1.78–2.08 mm long, 0.93–1.6 mm diam., external surface papillate, internal surface with a dense ring of moniliform trichomes from the anthers apex to the lobes base, sparsely pubescent between the anthers, and glabrous on the base, 4-lobate, corolla lobes 0.93–1.51 × 0.66–1.11 mm, subtriangular, external and internal surface papillate, rounded in preanthetic bud, this ca 1.09 mm diam., apex rounded; stamens included, inserted at the middle of the corolla tube, filaments 0.22–0.27 mm long, anthers 0.62–0.93 mm long, orbicules present covering uniformly the inner wall of dehiscent anthers, pollen 5-zonocolpate, circular outline in polar view, small-sized (P = 17–22 µm), prolate-spheroidal to prolate (P/E = 1.13–1.4), long and narrow ectocolpi (10–12 µm long), endocingulum (3)4–5 µm wide, tectum psilate microspinose, tipped microspines 0.2–0.4 µm long, distributed mostly around the ectocolpi, exine 0.8–1.4 µm thick; style included, 0.16–0.26 mm long, stigma 0.19–0.27 mm long, bilobate, lobes inconspicuous; nectariferous disk entire, 0.52–0.79 mm diam., with striate cells. Capsule 3–3.74 × 1.73–2.67 mm, obovate in outline, strongly compressed parallel to the septum, 1–3 acrodromous ribs slightly marked on the dorsal surface, glabrous, calyx lobes persistent, dehiscent from the apex downwards, valves persistent from which the seeds are shed after dehiscence, septum persistent, 2.69–3.65 × 1.54–2.15 mm. Seeds 2, 2.15–2.92 × 1.37–1.9 mm, broadly obovate in outline, strongly compressed, ventral surface covered by diffuse strophiole, 0.68–0.96 × 0.35–0.62 mm, dorsal surface slightly convex, testa subtuberculate, with digitallike cells pressed (37.37–93.87 × 17.98–34.18 µm), radially arranged.
Distribution, habitat, and phenology
Psyllocarpus itakangapyra sp. nov. grows on sandy and rocky soils in the “campo rupestre” vegetation (sensu Silveira et al. 2016), at ca 1300 m a.s.l. Currently it is only known from the municipality of Itacambira, in the micro-region of Grão Mogol, northern Minas Gerais (Fig. 7). However, future botanical expeditions to this region may increase the distributional range of this species. Specimens with flowers and fruits were collected in October and January.
Preliminary conservation status
Psyllocarpus itakangapyra sp. nov. does not occur within the limits of any protected area in Minas Gerais. It presents EOO and AOO equal to 1471 km 2 and 20 km 2 (kml file available as Supp. file 1). Therefore, we believe that this species would be considered endangered (EN B2abiii) in an official IUCN red list assessment, based on its EOO less than 5000 km 2 and AOO less than 500 km 2, occurrence in five locations, and continuing decline inferred on quality of habitat due to the impacts on the “campo rupestre” vegetation, which in this case is associated with the expansion of eucalyptus plantations in the region, as noticed by us during fieldwork.
description: Published as part of Sobrado, Sandra V., do Carmo, João A. M., Simões, André O. & Salas, Roberto M., 2022, Two new species of Psyllocarpus (Spermacoceae, Rubiaceae) from the state of Minas Gerais, southeastern Brazil, pp. 161-176 in European Journal of Taxonomy 806 on pages 163-165, DOI: 10.5852/ejt.2022.806.1713, http://zenodo.org/record/6402852