Maranta sophiana Yoshida-Arns, F. Fraga & J.M.A. Braga, 2019

Yoshida-Arns, Karla Norye, Fraga, Fernanda Ribeiro De Mello, Freire, Talvanis Lorenzetti & Braga, João Marcelo Alvarenga, 2019, Maranta sophiana (Marantaceae), a new species from the Brazilian Amazon, Phytotaxa 388 (3), pp. 247-252 : 249

Maranta sophiana Yoshida-Arns, F. Fraga & J.M.A. Braga , sp. nov. ( Figs. 1 − 4 )

Type:— BRAZIL. Pará: Santana do Araguaia, 100 km S of Redenção on road PA-150 to Barreiras dos Campos. Fazenda Inajaporã between Rio Inajazinho and Rio Inajá, approx., 210 m, 8°45’S, 50°25’W, 18 February 1980, T. Plowman, G. Davidse, N. A Rosa, C. S. Rosário & M. R. dos Santos 8860 (holotype NY barcode 01292260!; isotypes HAMAB accession 4910!, IAN accession 162138!, INPA accession 122657!, MO barcode 2767081!) .

Diagnosis:— Maranta sophiana is unique in the genus by presenting longitudinally ridged ovary and capsules.

Caulescent, erect herb profusely branched with elongated internodes, supporting at apex a cluster with 2–4 branches of different sizes, each branch subdividing into 1–2 clusters intercalated by internodes that becomes shorter distally. Cataphylls up to 20 cm long, tomentose to puberulous at base, glabrous at apex. Leaves homotropic, immaculate-green; leaf sheath 12 − 35 × 0.5 − 1 cm, glabrous, apex biauriculate; petiole absent; pulvinus 0.2 − 0.3 cm long, adaxially with deciduous tufts of erect trichomes, abaxially glabrous; leaf blade 13 − 30 × 3 − 6 cm, narrowly elliptic, glabrous, base cuneate, apex acuminate. Inflorescence 1 − 4 − nodate, 25 − 42 cm long, terminal, composed of 4 − 8 florescences; peduncle 9 − 17 cm long, tomentose, prophyll 4 − 7.5 × 0.3 − 0.6 cm, linear-lanceolate, glabrous, apex acute,; rachis 15 − 35 cm long, tomentose, becoming glabrous at apex; bracts 3.5 − 6 × 0.3 − 0.6 cm, linear-lanceolate, slightly cymbiform, glabrous, apex acute, 1 per florescence; florescence prophyll 2 − 4 × 0.3 − 0.5 cm, linear-lanceolate to narrow-lanceolate, slightly cymbiform, glabrous, apex acute, cymules 4 − 9 per bract, 2-flowered, dolichoblastic, glabrous; cymule peduncle 3 − 5 cm long, pedicels 0.4 − 0.5 cm and 0.9 − 1.5 cm long, respectively. Flowers 17 − 22 mm long, glabrous; sepals 13 − 18 × 4 − 6 mm, narrow-lanceolate, slightly cymbiform, apex acute, erect; corolla tube 7 − 9 mm long, lobes 10–17 × 4 − 6 mm, elliptic, apex rounded; 2 outer staminodes 9 − 15 × 5 − 7 mm, obovate, apex rounded to acute; callose staminode 12 − 18 × 6 − 8 mm, obovate, apex rounded to acute; cucullate staminode 8 − 15 × 3 − 5 mm long, appendage patent; fertile stamen 1 − 3 mm long, staminal appendage 2 − 3 mm long, anther ca. 1 mm long; ovary 2 − 3 × ca. 1 mm, longitudinally ridged; style 4 − 5 mm long, recurved. Capsules 15 − 22 mm long, ellipsoid, trigonous, longitudinally ridged, glabrous, crowned by persistent and erect sepals.

Distribution— Maranta sophiana occurs in the eastern Amazon region, in the State of Pará, Brazil ( Fig. 3 ). The only known collection was outside a conservation unit. In the last decades this region has been drastically deforested, and therefore this species is probably already in a threatened situation.

Etymology:— The new species is named after the daughter of the first author, Sophia Yoshida Arns.

Morphological affinities:— Maranta sophiana is the only species of the genus with longitudinally ridged ovary and fruits. At first glance, it may be confused with M. linearis , but differs by having a caulescent habit (vs. rosulate), absent petiole (vs. present), pulvinus with deciduous tufts of erect trichomes on the adaxial side (vs. hirtellous to hirsute), very long inflorescence length with 4 − 8 florescences (vs. short with 2 florescences), and longitudinally ridged ovary and capsule (vs. smooth) ( Fig. 4 , Table 1).

Figures

FIGURE 1. Maranta sophiana. A. habit; B. florescence prophyll; C. stamen with appendix; D. cucullate staminode; E. callose staminode; F. and G. Outer staminodes; H. pistil.

FIGURE 2. Holotype of Maranta sophiana (NY barcode 01292260). Photo courtesy of the New York Botanical Garden.

FIGURE 3. Distribution of Maranta sophiana in Brazilian Amazon.

FIGURE 4. Key morphological features of Maranta sophiana. A. Fruits; B. Ovary; C. Scanning microscopy detailing a ridged ovary.