Mitracarpus fernandesii E. L. Cabral, Sobrado & E. B. Souza, 2013

Cabral, Elsa L., Sobrado, Sandra V. & Souza, Elnatan Bezerra de, 2013, Three new species of Mitracarpus Zucc. (Rubiaceae) from Brazil, Candollea 68 (1), pp. 139-146 : 145

Mitracarpus fernandesii E. L. Cabral, Sobrado & E. B. Souza , spec. nova ( Fig. 5 , 2 C-F).

Typus: BRAZIL. Ceará: Planalto da Ibiapaba, Mun. Pacujá, Distrito Bom Gosto , Serrinha , 04°03’03’’S 40°42’25’’W, 190 m, 26.VIII.2009 (fl, fr), E. B. Souza, M. F. Mata, I. M. Andrade, J. W. A. Nogueira & M. O. M. Mesquita 1737 (holo-: HUVA!; iso-: CTES!).

Mitracarpo longicalyci affinis, se dab eo foliis pseudoverticillatis (vs oppositis), glomerulis terminalibus 1-1.5 cm in diam. et axillaribus 0.5-1 cm in diam. (vs 9-12 mm et 6- 9 cm), corolla 5-6.5 mm longa et tubo 4.5-5.2 mm longo (vs 3-5 mm et 2-3.5 mm longo), lobis longioribus calycis dimidio tubo corollae aequalibus (vs ultra medium tubi corollae),seminibusdorso sine depressione semicirculari (vs cum depressione semicirculari), differt.

Erect, branched herb, (5-) 10-37 cm tall, lateral branches opposite, stems quadrangular, pilose, 1-3 mm broad, internodes 1-9 cm long. Leaves pseudoverticillate, leaf-blades 9-40 × 3- 11 mm, lanceolate, chartaceous, base attenuate into a pseudopetiole, secondary veins 3-4 pairs, upper surface puberulous, lower surface pilose on the nerves, margins scaberulous; stipular sheath pilose, 1.5-3 mm long, bristles 5-7, 1- 3 mm, linear, glabrous. Inflorescence of terminal and 1-3 axillary glomerules, globose, many-flowered, the terminal glomerule 1-1.5 cm wide, the axillary 0.5-1 cm wide; involucral bracts 4-6, unequal, puberulous, violet or purple at the middle or lower third, 2 pairs generally longer than the glomerule (larger 20-46 × 4-11 mm; smaller 6- 15 × 1-3 mm), but sometimes 1 pair of bracts shorter than the glomerule, this located between the flowers. Flowers pedicellate, pedicel 0.7-1 mm long, hyphantium 1-1.5 mm long, turbinate, glabrous; calyx 4-merous, 2 large lobes, 2-2.3 mm long, up to half the length of the corolla tube, margins scabrid, lanceolate, greenish, 2 small lobes, 1.3-1.5 mm long, triangular, scabrid. Corolla white, 5-6.5 mm long, infundibuliform, inside with moniliform hairs in the lower third of the tube, outside glabrous; tube 4.5-5.2 mm long; lobes 1-1.5 mm long, glabrous. Stamens subsessile, anthers 0.8 mm. Style 4-5 mm long, stylearms 0.4-1 mm long, papillose. Capsule 1 × 1 mm, obovoid, glabrous. Seeds obovoid, 0.7-1 × 0.5-0.7 mm, brown, ventral face with an X-shaped groove, densely covered with granular excrescences, dorsal face with a weak central cruciform depression and angular depressions caused by the extensions of the ventral groove, testa reticulate in the depression and reticulateareolate in the rest of the surface ( Fig. 3 J-N).

Distribution and habitat. – Brazil, Ceará, growing in Caatinga, in transition to Cerrado on sandy soils between rocks.

Etymology. – Mitracarpus fernandesii is dedicated to the eminent botanist Afrânio Fernandes, who has greatly contributed to our knowledge of the Ceará Flora.

Paratypi. – BRAZIL. Ceará: Mun. Pacujá, Distrito Bom Gosto , Serrinha , 04˚03’10’’S 40˚42’12’’W, 220 m, 26.VII.2009, E. B. Souza & al. 17 40 ( CTES, HUVA); Mun. Pacujá, Distrito Bom Gosto , Serrinha , 04˚03’10’’S 40˚42’12’’W, 220 m, 16.III.2011, E. B. Souza & al. 2066 ( HUVA); Mun. Pacujá, Distrito Bom Gosto , Serrinha , 04˚03’10’’S 40˚42’12’’W, 220 m, 16.III.2011, E. B. Souza & al. 2069 ( HUVA).

Figures

Fig. 5. – Mitracarpus fernandesii E. L. Cabral, Sobrado & E. B. Souza. A. Habit; B. Stipular sheath; C. Leaf-blade; D. Flower; E. Corolla; F. Hypanthium, style and stigma; G. Dehiscent fruit; H-J. Seed; H. Dorsal view; I. Ventral view; J. Lateral view. [Souza & al. 1737, HUVA] [Drawing: L. Simón]

Fig. 2. – Mitracarpus carajasensis E. L. Cabral, Sobrado & E. B. Souza: A. Habit; B. Terminal glomerule. Mitracarpus fernandesii E. L. Cabral, Sobrado & E. B. Souza: C. Habit; D. Pseudoverticillate leaves; E. Terminal glomerule,1 pair of bracts located between the flowers are shown; F. Flowers of the axillary glomerule. [Photos: A-B: P. L. Viana; C-F: E. B. Souza]

Fig. 3. – Seed morphology (SEM-graphs). Mitracarpus carajasensis E. L. Cabral, Sobrado & E. B. Souza: A. Ventral view; B. Lateral view, notice the extensions of the ventral groove and the dorsal face depression; C. Dorsal view; D. Detail of reticulate-foveate testa. Mitracarpus federalensis E. L. Cabral, Sobrado & E. B. Souza: E. Ventral view; F. Lateral view, notice the extensions of the ventral groove; G. Dorsal view; H. Detail of testa of the lateral face, showing the hydrated papillas; I. Detail of testa of the dorsal face, showing the dehydrated papillas. Mitracarpus fernandesii E. L. Cabral, Sobrado & E. B. Souza: J. Ventral view; K. Lateral view, notice the extensions of ventral groove and dorsal depression; L. Dorsal view; M. Detail of reticulate-areolate testa of the dorsal angle; N. Detail of reticulate testa of the dorsal depression [Scale bars: A-C, E-G, J-L: 0.25 mm; D, H-I, M-N: 50 µm]. [A-D: Giorni & al. 196, BHCB; E-I: Fonseca & Alvarenga 4582, IBGE; J-N: Souza & al. 1737, HUV]