Mitracarpus carajasensis E. L. Cabral, Sobrado & E. B. Souza 2013, spec. nova
Creators: name: Cabral, Elsa L.
name: Sobrado, Sandra V.
name: Souza, Elnatan Bezerra de
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Gentianales
Rubiaceae
Mitracarpus
Mitracarpus carajasensis

description: Mitracarpus carajasensis E. L. Cabral, Sobrado & E. B. Souza, spec. nova (Fig. 1, 2 A-B).
Typus: BRAZIL. Pará: Canaã dos Carajás, 6°23’1’’S 50°23’10’’W, 753 m, 16.III.2009, fl fr, V. T. Giorni, P. L. Viana, L. M. Versieux, L. M. Garcia, L. V. C. Silva & D. S. Silva 196 (holo-: BHCB!; iso-: CTES!).
Mitracarpo parvulo affinis, sed ab eo habito erecto (vs caespitoso), caulibus glabris (vs pubescentibus), foliis 20- 29 mm longis et 1-2 mm latis (vs foliis 7-15 mm longis et 1-4 mm latis), setis stipularibus 4-5 (vs 5-7), 2(-4) bracteis involucralibus foliaceis glomerulis inflorescentiae quatruplo longioribus (vs 4 bracteis inequalibus in glomerulis terminalibus), seminibus dorso lineis 2 cruciformiter depressis (vs sine depressione dorsali), differt.
Simple or sparsely branched, erect herb, 15-25 cm tall. Stems subcylindrical to quadrangular, glabrous, internodes 2.5-5 cm long. Leaves sessile, leaf-blades 20-29 × 1-2 mm, linear, glabrous, apex attenuate, base acute, margins revolute, scaberulous, secondary veins obscure. Stipules 1-1.5 mm long, ribs and bristles pilose basally violet, bristles 4-5, ca. 1-1.5 mm, linear, glabrous. Inflorescence a terminal glomerule, 5-6 mm wide, subtended by 2(-4) foliaceous bracts, 4 times longer than the glomerule, 1-2 axillary glomerules also present. Flowers with hypanthium 0.5- 1 mm long, glabrous, calyx 4-merous, 2 large lobes, 1.3-2 mm long, subtriangular, exceeding the corolla tube, greenish, margins ciliate; 2 small lobes, ca. 0.5-1 mm long, hyaline; corolla white, 2-3 mm long, infundibuliform, tube 1.3 mm long, inside with moniliform hairs around the tube’s base, papillose inside and outside. Stamens subsessile, filaments 0.1-0.2 mm long, anthers 0.5 mm. Style 1.5-2 mm long, style-arms 0.1-0.3 mm long, papillose. Capsule 1 × 1 mm, glabrous. Seeds obovoid, 0.6- 1 × 0.6 mm, light brown; the ventral face with an X-shaped groove covered with whitish granular excrescences and the dorsal face with central cruciform depression and angular depressions caused by the extensions of the ventral groove, testa reticulate-foveate with irregularly outlined cells (Fig. 3 A-D).
Distribution and habitat. – Brazil, in Pará State, in the microregion of Canaã dos Carajás and Parauapebas. It grows in rocky field on “canga’’. The canga vegetation is characterized by the patches of saxicolous scrubby vegetation on the iron outcrops, usually on mountain summits (SECCO & MESQUITA, 1983).
Notes. – Mitracarpus carajasensis is related to M. parvulus K. Schum., the corolla tube being shorter than the lobes of the calyx. Both have opposite leaves and lack brachyblasts. However, the latter is a cespitose herb, branched from the base, with marked pubescence and seeds without depressions on the dorsal faces.
Paratypi. – BRAZIL. Pará: Canaã dos Carajás, 6°21’30.69’’S 50°23’58.91’’W, 700 m, 18.V.2010, L.C.V. Silva&al.880 (BHCB, CTES); 6°20’34.32’’S 50°25’24.04’’W, 700 m, 19.V.2010, L. C. V. Silva & al. 889 (BHCB, CTES); 6°23’48.94’’S 50°22’21.84’’W, 728 m, 22.III.2012, A. J. Arruda & al. 773 (BHCB, CTES); 6°17’2.38’’S 50°20’13.13’’W, 580 m, 22.III.2012, A. J. Arruda & al. 779 (BHCB, CTES); 6°22’32.10’’S 50°22’58’’W, 715 m, 22.III.2012, P. B. Mayer & al. 1163 (BHCB, CTES); Serra da Bocaina, 6°19’35.39’’S 49°58’5.53’’W, 697 m, 20.IV.2012, A. J. Arruda & al. 960 (BHCB, CTES); Parauapebas, 6°11’1.63’’S 50°7’47.31’’W, 701 m, 23.III.2012, P. B. Mayer & al. 1166 (BHCB, CTES); 6°4’23.74’’S 50°11’35.08’’W, 554 m, 24.III.2012, P. B. Mayer & al. 1195 (BHCB, CTES); 6°9’13.18’’S 50°10’20.79’’W, 693 m, 25.III.2012, P. B. Mayer & al. 1229 (BHCB, CTES).
description: Published as part of Cabral, Elsa L., Sobrado, Sandra V. & Souza, Elnatan Bezerra de, 2013, Three new species of Mitracarpus Zucc. (Rubiaceae) from Brazil, pp. 139-146 in Candollea 68 (1) on page 140, DOI: 10.15553/c2013v681a19, http://zenodo.org/record/5746999