Anthurium pluricarinatum Camelo, Temponi, Baumgratz & Nadruz, 2023

Camelo, Mel C., Temponi, Lívia G., Coelho, Marcus A. N. & Baumgratz, José F. A., 2023, Taxonomic updates in Anthurium sect. Pachyneurium (Araceae) from the Brazilian Atlantic Forest, Phytotaxa 599 (2), pp. 109-125 : 111

Anthurium pluricarinatum Camelo, Temponi, Baumgratz & Nadruz , sp. nov. ( Figs. 1A–Q )

Anthurium pluricarinatum is most similar to A. affine Schott , but the new species differs by having petioles 3–6 ribbed on the abaxial surface (vs. petioles smooth or to <3-ribbed), spathe vinaceous to nigrescent, 2.0– 2.5 cm long. (vs. greenish and vinaceous striated, 4–17 cm long), peduncle greenish-vinaceous (vs. greenish), spadix greenish-vinaceous to purple at anthesis, 2.8–3.0 cm long. (vs. yellowish-greenish to yellowish, 3–19 cm long).

Type:— BRAZIL. Rio Grande do Norte, Maxaranguape, RN –160, subindo a duna ao lado da estrada principal, 5°26’5’’S, 35°17’52’’W; 20 m, 20 July 2019, M. C. Camelo et al. 111 (holotype RB 792031 !, isotypes RB!, UFRN!) .

Terrestrial: stem erect; roots numerous, dense, white, smooth; cataphylls and prophylls 8.0– 8.5 cm long, brownish, lanceolate, apex acuminate, persistent, decomposing into fibers at base. Leaves rosulate, erect; petioles 5.5–12.0 × ca. 0.4 cm, greenish, adaxial surface sulcate and acute margins, abaxial surface 3–6 ribbed; geniculum 0.5–0.8 cm long, greenish, proeminent; blades 21.5–22.5 × 5.3–15.0 cm, greenish, discolor, coriaceous, elliptic to obovate, apex acute, base acute to obtuse, with sharply wavy margins, glandular punctuations absent; leaf venation eucamptodromous; midrib greenish-yellow, prominent and acute on both surfaces, sometimes 1-ribbed in the median region; primary lateral veins 5–7 pairs, prominent, greenish-yellowish, ascendent; secondary lateral veins poorly developed or absent; collective veins absent. Inflorescences erect; peduncle 21.5–26.5 × 0.2 cm, greenish-vinaceous at anthesis, brownish at post-anthesis, 1-multi-ribbed; spathe 2–2.5 × 3–4 cm, vinaceous to nigrescent, coriaceous, striations absent, reflexed, ovate, apex acuminate, forming an obtuse angle with peduncle; spadix 2.8–3.0 × 0.5 cm, vinaceous at pre-anthesis, greenish-vinaceous to purple at anthesis, brownish to nigrescent at post-anthesis, cylindric, sessile or stipe 2–4 cm long, brownish, half as long to longer than spadix, with 7–10 flowers principal spiral and 6–8 flowers alternate spiral; ovary bilocular, ovule 1 per locule, placentation axile, funicle pilose; pollen grains whitish. Infructescence erect; berries 0.55- 0.61 x 0.36-0.41 cm, oblong, reddish; seeds 0.47–0.51 × 0.19–0.21 cm, 1–2 per berry, ellipsoid, flattened unilateraly, yellowish, wrinkled, with mucilage.

Phenology:— Anthurium pluricarinatum was collected in flower in July and with fruit in May.

Etymology:—The specific epithet “pluricarinatum” is due to the multi-ribbed petiole.

Distribution and habitat:— Anthurium pluricarinatum was found in the Maxaranguape municipality, Rio Grande do Norte state, in the Brazilian Atlantic Forest region, in Restinga and /or dune-fixing vegetation ( IDEMA 2008), at 20 m elevation above sea level ( Fig. 2 ).

Conservation status:—The species is known only to the type locality. However, the natural habitat where it occurs has suffered high human impact, mainly due to deforestation, urban development, and tourism, whichrequires urgent action to preserve the environment. Based on the species distribution (AOO 4.000 km 2 based on user defined cell width of 2km) it was considered a Critically Endangered (CR) according to the IUCN Criteria ( IUCN 2021).

Paratypes:— BRAZIL, Rio Grande do Norte: Maxaranguape, RN–160, subindo a duna ao lado da estrada, 20 July 2019, M . C . Camelo 112 ( RB!); Maxaranguape, RN –160, subindo a duna ao lado da estrada, 20 July 2019, M . C . Camelo 113 ( RB!). Maxaranguape , RN-160, subindo a duna ao lado da estrada, 26 May 2023, Nadruz 4093 ( RB!) .

Notes:—Among the sections established for Anthurium , the one that best circumscribes A. pluricarinatum is the Anthurium sect. Pachyneurium by the characteristics of the involute prefoliation, short-petiole, collective vein absent and primary lateral veins proeminent ( Croat 1991). The new species have a set of characters described, the set of other characters described in the protologue distinguishes it from the other congeners, mainly by the petiole>3 ribbed on the abaxial surface, erect inflorescence, with greenish-vinaceous peduncle, vinaceous to nigrescent spathe, reflexed, ovate, greenish-vinaceous to purple spadix and stipe 2–4 cm length ( Fig. 1 ).

Figures

FIGURE 1. Anthurium pluricarinatum. A. Habit. B. Detail of entire plant. C. Detail of the multi-ribbed petiole. D. Detail of leaf blade. E. Cross-section of the midrib. F. Cross-section of multi-ribbed petiole in the abaxial surface. G. Detail of leaf blade margins and stipulate spadix.H. Inflorescence erect in pre-anthesis.I. Spathe erect in pre-anthesis, purple spadix.J. Inflorescence erect,reflexed spathe, greenishvinaceous spadix. K. Purple spadix at anthesis. L. Detail of purple spadix with pollen grain.M. Infructescence erect in pos-anthesis, spadix brownish with immature berries. N. Detail of immature berries vinaceous. O. Infructescence with 1 berry. P. Detail of reddish berry. Q. Detail of seeds, yellowish, wrinkled.

FIGURE 2. Distribution map of Anthurium sect. Pachyneurium from the Brazilian Atlantic Forest Domain, including a new species Anthurium pluricarinatum. Data Source: IBGE (2017). Note: The colors represent the different types of vegetation and the abbreviation on the map (i.e., CE, RN, PB, PE, etc.) are the states of Brazil.