Anthurium itacarense K.M.Pimenta & Mayo

Pimenta, Karena M., Marinho, Lucas C., Amorim, André M. & Mayo, Simon, 2024, Two new species of Anthurium sect. Urospadix (Araceae) endemic to the restinga vegetation of Bahia, Brazil, Phytotaxa 641 (2), pp. 138-148 : 143-145

Anthurium itacarense K.M.Pimenta & Mayo , sp. nov. ( Figs 4 , 5 )

Anthurium itacarense shares the following characters with A. bellissimum : creeping stem, persistent cataphylls, leaves with midrib flattened adaxially and prominent abaxially. The species can be distinguished by the exclusively rupicolous habit of A. itacarense (vs. terrestrial), leaf blade elliptic with cuneate base (vs. ovate with concavo–convex base), smaller leaf blades (5.8–10.5 vs.12.0– 23.8 cm long), peduncle size (7.5–11.5 vs.30–34(–50) cm long), spathe size (3.6–5.2 × 1.0–1.2 vs. 9.0–15.5 × 2.5–3.8 cm), spadix size (4–5 × 0.6–0.8 vs. 9.5–17.7 × 0.9–1.3 cm), and stipe size (0.2–0.3 vs. 1.4–3.0(–7.2) cm long), flower number in the primary spiral (3–4 flowers vs.6 flowers), and tepal colour (orange vs.darkred).

Type:— BRAZIL. Bahia: Município Itacaré, trilha de acesso à prainha na praia da Ribeira , 14º17’20,14”S 38º59’5,6”W, 25 February 2019, fl., K.M. Pimenta & L.C. Marinho 898 (holotype HUEFS no. 262397!, isotype CEPEC!) .

Herb; rupicolous. Stem creeping, reddish in cross-section with colorless exsudate when cut; internodes 0.5–1.0 × ca. 1.6 cm; cataphylls and prophylls ferrugineous in alive and brown in dry, persistent, entire, membranaceous, apical cataphyll 5.3–6.6 cm long. Leaf: sheath 1.0– 1.2 cm long; petiole 7.5–12.0 × 0.36–0.46 cm, light green to yellowish, rounded abaxially, slightly canaliculate adaxially; geniculum 1.4–2.2 × 0.45–0.68 cm, yellow-greenish, discolorous, canaliculate adaxially; leaf blade 19–35 × 5.8–10.5 cm, elliptic, green, discolorous, chartaceous in vivo and papyraceous in sicco, erect, glossy on both surfaces, glandular dots absent, apex straight, base cuneate; basal veins absent; midrib acute; secondary veins 6–8 per side, impressed adaxially and slightly prominent abaxially; collective veins arising from the base, running at 0.5–1.0 cm from blade margin. Inflorescence: peduncle 7.5–11.5 × 0.4–0.5 cm, slightly cryptic (inflorescence and leaf blade positioned at the same height level), pinkish at base and green from middle to apex, cylindrical, erect; spathe 3.6–5.2 × 1.0– 1.2 cm, elliptic, green with margins and apex vinaceous, patent in anthesis, position in fruit not seen, chartaceous in vivo and papyraceous in sicco, spathe margins decurrent for 0.2–0.3 cm, meeting at acute angle; stipe 0.2–0.3 cm long, cylindrical; spadix 4–5 × 0.6–0.8 cm, cylindrical, green, 0.2–0.3 × 0.5–0.6 mm, number of flowers in the primary spiral 3–4; flowers 0.45–0.5 × 0.5–0.6 cm, tepals orange. Berries not seen.

Etymology: —The epithet honors the municipality of Itacaré, which includes the type locality of the new species.

Phenology:— Anthurium itacarense , based on the records, indicate two different flowering periods from February to April and from October to December.

Distribution and Conservation status: —Although the southern Bahia coastal forests have been the focus of field expeditions for over 70 years, Anthurium itacarense is known from only two collections in the same locality [B2a], the Praia da Ribeira beach ( Fig. 3 ). Although the region is part of the Costa de Itacaré/Serra Grande Environmental Protection Area ( Bahia 2003), where construction is regulated, the Praia da Ribeira beach is one of the busiest in the region, with a large circulation of tourists during the summer [B2biii]. Due to the few numbers of localities where A. itacarense occurs, the observed decline of habitat quality, in addition to the broad ornamental appeal of the plant and common to the family, we assessed the species as Critically Endangered [B2a, biii].

Recognition and discussion: — Anthurium itacarense belongs to Anthurium sect. Urospadix . It is characterized by its rupicolous habit ( Figs. 4A , 5A ), elliptic leaf blade with a cuneate base ( Figs. 4C , 5C ), and flowers with orange tepals ( Figs. 4H , 5D–E ). The species can be confused with A. bellissimum (e.g. the specimen Matos Silva 2714 represents different specimens, consequently different species, in the two herbaria where it is deposited: A. bellissimum in ALCB and A. itacarense in HUEFS). Both species are sympatric, but can be distinguished by the general smaller size of A. itacarense (see diagnosis), leaf blade base (cuneate vs. concavo-convex in A. bellissimum ), and, especially by the number of flowers in the primary spiral (3–4 vs. 6 in A. bellissimum ) and tepal colour (orange vs. dark red in A. bellissimum ) (see Tab. 1 ).

Additional specimens examined (paratypes): — BRAZIL. Bahia: Mun. Itacaré, mata em frente à Praia da Ribeira , próximo ao córrego, 20 April 1989 (fl.), L.A. Matos Silva et al. 2714 ( HUEFS! non ALCB!) ; a 3 km ao sul de Itacaré , mata a beira mar, 8 December 1979 (fl.), S. Mori et al. 13078 ( CEPEC!) ; Litoral Sul, Mata da Botinha , 14º10’53”S, 39º42’27”W, 28 October 2008 (fl.), C.H.A. Ramos et al. 576 ( ALCB!). Mun. Jandaíra, Litoral Norte, 11º33’S, 37º47’W, 2 February 2014 (fl.), S.F. Gomes et al. 1314 ( MBM photo!) .

Figures

FIGURE 3. A. Geographic distribution of Anthurium bellissimum (black circles) and A. itacarense (white star). B. Detail showing the Itacaré municipality downtown and the type locality of both species. C. General view of Praia da Ribeira beach, the type locality of A. itacarense.

FIGURE 4. Anthurium itacarense. A. Habit. B. Detail of creeping stem apex. C. Detail of leaf blade base. D. Cross section of petiole. E. Cross section of geniculum. F. Inflorescence. G. Stipe. H. Flowers. I–J. Tepals. Illustration by K. Pimenta.

FIGURE 5. Anthurium itacarense. A. Habit with creeping stem detail. B. Detail of creeping stem apex. C. Leaf blade, detail showing cuneate leaf base. D. Inflorescence. E. Flowers showing orange tepals, stamens and stigma droplet. Photos by K. Pimenta.