Monotagma floribundum Hagberg & R.Erikss., 2011

Hagberg, Mats & Eriksson, Roger, 2011, New names in Monotagma (Marantaceae), Phytotaxa 20 (1), pp. 1-25 : 11

5. Monotagma floribundum Hagberg & R.Erikss. , sp. nov. ( Fig. 2E )

Monotagmatis rhodanthi et M. rosei similis , sed ab eis differt nodo inferiore synflorescentiae folio frondoso (vs. vagina tantum) instructo, et lamina ad basin cuneata (vs. cordata); etiam M. densiflori et M. angustissimi similis , sed ab eis differt axe principali synflorescentiae nodis pluribus (10–11 vs. 4–7).

Type:— BRAZIL. Amazonas : Itaituba–Jacareacanga road, km 85, Parque Nacional do Tapajós ( I. B. D. F.), Reserva Biológica Ramal do Pau Rosa, 14 November 1978, Silva & Rosario 3715 (holotype MG, isotype NY) .

Herb 1.5–2 m tall. Rhizomes subterraneous. Shoots bearing up to ca 7 distichous basal leaves. Ultimate basal leaf with sheath ca 80 cm long, ± coriaceous, appressed-hirtellous throughout, not auriculate; petiole 11–28 cm long, laterally ± flattened, without an adaxial groove, puberulent to rarely appressed-hirtellous; pulvinus 2–5.5 cm long, laterally ± flattened, appressed-hirtellous throughout, without annulus; blade narrowly oblong, ± subchartaceous when dry, base cuneate, apex acuminate, oblique (apex displacement 0.5–1.5 cm), 39–72 × 7.5–13 cm, length from base to broadest part 16–38 cm, adaxial surface not papillose, hirtellous to hirsute at apex, abaxial surface not papillose, hirtellous to hirsute throughout. Synflorescence 10–11-nodate with 15–60 florescences, lowermost node with a well-developed leaf, sheath 5–12 cm long, petiole 0–2.5 cm long, each subsequent node with a bladeless sheath, first internode 0.7–6.5 cm long, peduncle ca 120 cm long, appressedhirtellous to appressed-hirsute. Main florescence 4.4–8.3 cm long with 5–13 unilaterally arranged bracts, first internode 0.3–0.5 cm long, peduncle 0.4–0.6 cm long; lowermost bract 1.4–1.9 cm long, reddish, papyraceous, puberulent throughout or at least apically; first prophyll 10–11 mm long, glabrous or puberulent throughout. Flowers ca 3 per bract; pedicel 0.5–1 mm long; ovary 1–1.5 mm long, puberulent apically, rarely throughout; sepals 4.5–7 × ca 1 mm, apex obtuse; corolla tube 8.5–15 × 1–1.5 mm, outside towards lobes hirtellous to puberulent, rarely glabrous, inside hirtellous in mouth, lobes 3.5–5 × 2–3 mm, only slightly open, leaving a small pore at apex; outer staminode rudimentary or absent; stamen 3–3.5 mm long, appendage tapering to base of theca, theca 1–1.5 mm long; callose staminode 3–3.5 × ca 3 mm, 0.5–1 mm petaloid apically, with a shelf-shaped callus at 1.5–2 mm from apex; cucullate staminode 3.5–4 mm long, lateral appendage 1–1.5 mm long; style ca 3.5 mm long (untripped), or 3–3.5 mm long (tripped). Capsule 7–11.5 × 3–4 mm; aril with two flattened unilateral lobes.

Distribution:— Brazil, in the eastern part of the lowland Amazon Basin.

Discussion:— Monotagma floribundum usually has rudimentary (<0.5 mm long) outer staminodes. It is most similar to M. rhodanthum and M. roseum , from both of which it differs by having a leaf blade subtending the synflorescence (vs. a bladeless sheath) and cuneate leaf blade bases (vs. cordate). It is also similar to M. densiflorum and M. angustissimum , from which it differs by having a more richly branched synflorescence (10–11 vs. 4–7 nodes).

Paratypes:— BRAZIL. Amazonas: 4 km S of Terra Preta, Rio Abacaxis , July 1983, Hill et al. 12967 ( INPA) ; Manicoré , August 1976, Mota s. n. ( INPA) ; Manaus–Porto Velho road km 498, October 1983, Rodrigues 10454 ( INPA) . Pará: Rio Tapajós , morros de Quataguara (Coatáqurá), Ducke s. n. ( RB) ; Rio Madeira, Rio Abacaxis , October 1957, Fróes 33667 ( IAN) ; Monte Dourada , November 1978, Pires & Silva 1463 ( GB) ; Santos 424 ( MG, NY) .

Figures

FIGURE 2. Monotagma seeds (A–C), habits (D–E, G–H), and synflorescence (F). A, M. laxum (Hagberg et al. 330); B, M. rudanii (Hagberg et al. 331); C, M. tuberosum (Hagberg & Medin 362); D, M. exile (Cremers 8321); E, M. floribundum (Bamps 5222); F, M. paradoxum (Schunke 5739); G, M. roseum (Andersson 10616); H, M. septentrionale (Jangoux 10164).