Monotagma paradoxum Hagberg & R.Erikss., 2011

Hagberg, Mats & Eriksson, Roger, 2011, New names in Monotagma (Marantaceae), Phytotaxa 20 (1), pp. 1-25 : 13-14

8. Monotagma paradoxum Hagberg & R.Erikss. , sp. nov. ( Fig. 2F )

Bracteis roseis et nodo inferiore synflorescentiae vagina tantum instructo, Monotagmatis rhodanthi et M. rosei similis ; a M. rhodantho differt folio abaxiali pagina virella (vs. cerosa et glaucescenti) et laminae costa ad apicem attingenti (vs. ad 2/3 laminae longitudine attingenti); a M. roseo differt laminae apice valde obliquo et synflorescentiae axe principali 7–8 (vs. 2–4) nodis.

Type:— PERU. San Martín: East of Puente Palo Blanco, Tocache Nuevo , 800–900 m, 16 December 1972, Schunke 5739 (holotype F, isotype L) .

Herb 1.4–1.7 m tall. Rhizomes subterraneous, branched to form clusters of a few shoots, each shoot bearing 3–6 distichous to ± spirodistichous basal leaves. Ultimate basal leaf with sheath 21–58 cm long, chartaceous to subcoriaceous, appressed-hirsute to appressed-hirtellous throughout, usually not auriculate; petiole 5–63 cm long, laterally ± flattened, without an adaxial groove, glabrous to puberulent; pulvinus 1.6–4.6 cm long, laterally ± flattened, puberulent adaxially, without annulus; blade narrowly ovate, ± chartaceous when dry, base ± obtuse, apex acuminate, oblique (apex displacement 1.4–3 cm), 26–58 × 9–16 cm, length from base to broadest part 9–20 cm, adaxial surface not papillose, puberulent to hirtellous along midrib, major lateral nerves and margins, and at apex, abaxial surface not papillose, glabrous or appressed-pilose at apex. Synflorescence 4–8-nodate with 8–31 florescences, each node with a bladeless sheath, lowermost one 2.6–7.2 cm long, first internode 2.8–5.7 cm long, peduncle 18–124 cm long, appressed-hirtellous to appressed-hirsute. Main florescence 4.5–6.5 cm long with 10–12 ± distichous to unilaterally arranged bracts, first internode 0.5– 0.6 cm long, peduncle 0.6–0.8 cm long; lowermost bract 1.4–1.7 × ca 1 cm, reddish, subchartaceous, puberulent at apex or rarely throughout; first prophyll 10–12 mm long, glabrous or slightly hirsute at apex. Flowers 3–5 per bract, reddish; pedicel 0.5–1 mm long; ovary 1–3 mm long, glabrous or puberulent apically; sepals 5.5–8.5 × 2–3 mm, apex obtuse; corolla tube 11–15 mm long, outside glabrous, rarely puberulent above sepals, inside hirsute to hirtellous except for a glabrous basal portion, lobes 4.5–6 × 3–3.5 mm, only slightly open, leaving a pore at apex; outer staminode 3–7 × 0.5–3 mm, rarely absent, apex bilobed or entire; stamen 3.5–4.5 mm long, with appendage reaching ca 0.5 mm above base of theca, theca 1–1.5 mm long; callose staminode 4.5–5 × 3.5–4 mm, fleshy throughout, with a shelf-shaped callus at 1.5–3 mm from apex; cucullate staminode 3–4.5 mm long, lateral appendage 1–1.5 mm long; style 2.5–3 mm long (tripped). Capsule 10–16 × 4–5 mm; seed 9–14 × 3.5–4.5 mm; aril 1.5–3.5 mm long, with two flattened unilateral lobes.

Distribution and habitat:—Collected in the Río Huallaga valley in Peru and in southeastern Colombia, at 300–900 m elevation.

Discussion:— Monotagma paradoxum has small to rudimentary outer staminodes which are rarely absent. The other species with red bracts of sect. Monotagma lack the outer staminodes (small rudiments sometimes present). Monotagma paradoxum is most similar to M. septentrionale , but differs by having a bladeless sheath subtending the synflorescence (vs. a leaf blade). Bladeless sheaths are found also in M. roseum and M. rhodanthum , but probably due to parallell evolution.

Paratypes:— COLOMBIA. Vaupés: Yurupari, February 1944, Allen 3280 ( MO); Soratama, Río Apaporis , March 1952, Schultes & Cabrera 16088 (US) . PERU. Huánuco: Daniel Alomia Robles , June 1976, Schunke 9298 ( GB, MO) .

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).