Monotagma aurantispathum Hagberg & R. Erikss. 2011, sp. nov.
Creators: name: Hagberg, Mats
name: Eriksson, Roger
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Zingiberales
Marantaceae
Monotagma
Monotagma aurantispathum

description: 13. Monotagma aurantispathum Hagberg & R.Erikss., sp. nov.  (Fig. 4A)   
 Differt a speciebus caeteris Monotagmatis spathis aurantiacis ad anthesin imbricatis. M. smaragdini et M. flavicomi similis, sed ab eis differt staminodio exteriore anguste elliptico (vs. spathulato) apice integro (vs. emarginato).   
 Type:— PERU. Loreto: Brillo Nuevo on Río Yaguasyacu, trib. to Río Ampiyacu, 8 November 1977, Gentry & Revilla 20389 (holotype MO, isotype GB).   
Herb 1–1.5 m tall. Rhizomes subterraneous, branched to form clusters of a few shoots, each shoot bearing up to ca 6 irregularly arranged basal leaves. Ultimate basal leaf with sheath 24–37 cm long, subchartaceous to chartaceous, hirsute throughout, not auriculate; petiole 0.4–12 cm long, laterally flattened, hirsute; pulvinus 0.5–0.7 cm long, ± terete, hirsute throughout, without annulus; blade narrowly elliptic, papyraceous when dry, base cuneate to obtuse, apex caudate, centric, 24–33 × ca 10 cm, length from base to broadest part 12–15 cm, adaxial surface ± papillose, hirsute throughout, abaxial surface not papillose, hirsute throughout. Synflorescence 2–3-nodate with 3–7 florescences, first and sometimes also second node with a welldeveloped leaf, lowermost one with sheath 10–13 cm long, petiole absent or 0.3–0.5 cm long, pulvinus 0.3– 0.4 cm long, blade 18–33 × 8–10 cm, subsequent node with a bladeless sheath, first internode 2.7–6.8 cm long, peduncle 40–70 cm long, hirsute. Main florescence 5.2–9.2 cm long with 7–14 bracts, distichous and ± imbricate at anthesis, first internode 0.6–0.8 cm long, peduncle 0.8–2 cm long; lowermost bract 2.5–2.8 × 1.1–1.2 cm, narrowly elliptic, orangish, subchartaceous, hirsute throughout; first prophyll 15–17 mm long, hirsute throughout or at least on back and at apex. Flowers 5–6 per bract, white; pedicel 1–2 mm long; ovary 1.5–2 mm long, hirtellous apically; sepals 3.5–6.5 × ca 1 mm; corolla tube 18.5–20 mm long, outside glabrous or hirtellous throughout, inside hirtellous in mouth, lobes 4–5 × ca 3 mm; outer staminode 1–3 × 0.5–1 mm, narrowly elliptic, apex entire; stamen 3–3.5 mm long, theca 1–1.5 mm long; callose staminode ca 4.5 × 3–3.5 mm, 0.5–1 mm petaloid apically, with a shelf-shaped callus at ca 3 mm from apex; cucullate staminode ca 3 mm long; style 2.5–3 mm long. Capsule 10–12 × ca 3 mm; seed 10–11 × 2.5–3 mm, narrowly cylindrical; aril ca 1 mm long, tubular without lobes.  
 Distribution and habitat:—Collected in the western part of the Amazon Basin of Peru and Brazil, in lowland terra firme forests on latosol.   
 Discussion:— Monotagma aurantispathum is readily recognized by having orange bracts which are ± imbricate throughout anthesis. It is similar to M. smaragdinum and M. flavicomum, both of which have bracts spreading throughout anthesis. It differs from both by having outer staminodes that are smaller (1–3 × 0.5–1 vs. 5.5–7 × 2.5–5.5 mm) and narrowly elliptic (vs. spathulate) with entire apex (vs. bilobed), and shorter capsules (10–12 vs. 16–21 mm).   
 Paratypes:— BRAZIL. Amazonas: “Camatian” (probably Igarapé Camatiá near São Paolo da Olivença), January 1949, Fróes 24053 (IAN); Tabatinga, December 1945, Pires & Black 916 (GH, IAN). PERU. Loreto: Brillo Nuevo on Río Yaguasyacu, trib. to Río Ampiyacu, April 1977, Plowman et al. 6769 (GH); November 1981, Treacy & Alcorn 625 (F); Pongo de Manseriche, Río Marañón, 1924, Tessman 4631 (G, possibly mislabeled).
description: Published as part of Hagberg, Mats & Eriksson, Roger, 2011, New names in Monotagma (Marantaceae), pp. 1-25 in Phytotaxa 20 (1) on pages 18-20, DOI: 10.11646/phytotaxa.20.1.1, http://zenodo.org/record/4776634