Monotagma uliginosum Hagberg & R.Erikss., 2011

Hagberg, Mats & Eriksson, Roger, 2011, New names in Monotagma (Marantaceae), Phytotaxa 20 (1), pp. 1-25 : 21-22

15. Monotagma uliginosum Hagberg & R.Erikss. , sp. nov. ( Fig. 5A )

Synflorescentia congesta et laminae apice obliquo M. secundi et M. tomentosi similis , sed ab eis differt surculis caespitosis, scapo breviore (4–9 vs. 15–19 cm) et bractearum apicibus mucronatis (vs. acutis).

Type:— PERU. Loreto: Puerto Almendras W of Iquitos , 100 m, 11 November 1984, Maas 6264 (holotype AMAZ, isotypes GB, L, USM) .

Herb to ca 1 m tall, bearing 3–15 irregularly arranged basal leaves. Rhizomes elevated above ground supported by “stilt” roots, forming tussocks of up to 10 aerial shoots. Ultimate basal leaf with sheath 20–39 cm, papyraceous, yellowish green, hirsute, hairs sometimes appressed, not auriculate; petiole 10–19 cm long, laterally flattened, glabrous; pulvinus 1.1–1.3 cm long, ± terete or somewhat laterally flattened, dark green, puberulent adaxially, without annulus; blade narrowly elliptic, papyraceous, scalloped, base obtuse, apex caudate, oblique (apex displacement 0.6–1 cm), 30–38 × 9.6–14 cm, adaxial surface usually papillose, matt green, hirtellous along midrib and margins, and at apex, abaxial surface usually papillose, greyish green, glabrous or rarely appressed-puberulent along right margin and at apex. Synflorescence 4–5-nodate with many florescences in a dense ± ovoid cluster, each node with a bladeless sheath, lowermost 3.8–5.1 cm long, peduncle 4–9 cm long, terete, glabrous. Main florescence 2.2–3.8 cm long with 3–9 unilaterally arranged bracts, first internode 0.2–0.4 cm long, peduncle 0.2–0.4 cm long; lowermost bract 2.3–2.7 × 0.8–0.9 cm, greenish, apex mucronate, papyraceous, glabrous or slightly puberulent towards apex; first prophyll 23–25 mm long, bicarinate, puberulent to hirtellous on carinas and at apex or rarely glabrous; interphylls and bracteoles absent. Flowers 4–7 per bract, white; pedicel 0.5–1.5 mm long; ovary 2–3 mm long, glabrous or slightly puberulent apically; sepals 5–6 × 1–1.5 mm; corolla tube 17–18 × 1.5–2 mm, outside glabrous, inside glabrous or hirsute in mouth, lobes ca 6 × 3–3.5 mm; outer staminode ca 9 × 3–4.5 mm, emarginate; stamen 3–4 mm long, theca ca 1 mm long; callose staminode 6–7 × 4–5 mm, 1.5–2 mm petaloid apically, with a shelfshaped callus 4–5 mm from apex; cucullate staminode 3–4 mm long, appendage ca 1 mm long; style 3–3.5 mm long (tripped). Capsule ca 9 × ca 3 mm; seed 7.5–12.5 × 2.5–3.5 mm, reddish; aril 1.5–3.5 mm long, brownish, tubular without lobes.

Distribution and habitat:—Known only from the Iquitos region in Peru. It is found in swampy places in lowland forest on white sand.

Discussion:— Monotagma uliginosum is similar to M. secundum and M. tomentosum , with which it shares the congested synflorescence and leaf blades with ± oblique apex. It differs from both by the shoot system with aggregates of many shoots supported by “stilt” roots, forming large, elevated tussocks, and by having a shorter synflorescence peduncle (4–9 vs. 15–91 cm) and bracts with mucronate apex (vs. acute).

Paratypes:— PERU. Loreto: Varadero de Mazán , August 1972, Croat 19476 ( F, MO) ; Puerto Almendras ( CIEFOR) , 15 km W of Iquitos , February 1987, Hagberg & Medin 376 ( AMAZ, GB) .

Figures

FIGURE 5. Monotagma isotypes at GB. A, M. uliginosum; B, M. tuberosum.