Monotagma breviscapum Hagberg & R.Erikss., 2011

Hagberg, Mats & Eriksson, Roger, 2011, New names in Monotagma (Marantaceae), Phytotaxa 20 (1), pp. 1-25 : 10-11

4. Monotagma breviscapum Hagberg & R.Erikss. , sp. nov. ( Fig. 1D )

Rhizomate epigaeo et foliis basalibus spirodistichis Monotagmatis vaginati similis, sed ab eo differt scapo brevissimo (0–1.8 vs. 10–50 cm), praesentia petiolo, et pulvino annulo carenti.

Type:— BRAZIL. Amazonas: Manaus – Itacoatiara road (AM-10), 55 km E of first crossing of Rio Urubú , 10 March 1986, Andersson & Hagberg 1765 (holotype INPA, isotypes GB, S, US).

Herb 0.7–1.5 m tall. Rhizomes partly (to 50 cm) above ground and supported by “stilt” roots, suberect to trailing, distally branched to form clusters of up to 5 shoots, each shoot bearing 9–17 spirodistichous basal leaves. Ultimate basal leaf with sheath 5.5–26 cm long, chartaceous, tinged purple, glabrous except for hirsute base, auriculate; petiole 2.4–30 cm long, laterally ± flattened, tinged purple, with an adaxial groove, puberulent along the groove; pulvinus 1.1–1.9 cm long, laterally ± flattened, tinged purple, puberulent adaxially, without annulus; blade narrowly ovate to narrowly elliptic, ± subcoriaceous, slightly scalloped, base obtuse, apex acuminate, oblique (apex displacement 1.3–2.3 cm), 25–38 × 7.6–10 cm, length from base to broadest part 7.8–13 cm, adaxial surface not papillose, dark green, hirtellous to puberulent along midrib, major lateral veins and margins, and at apex, abaxial surface not papillose, greyish green, glabrous or hirtellous at apex, hairs sometimes appressed. Synflorescence 3–6-nodate with 5–9 florescences, lowermost node with a bladeless sheath, 2.6–7.5 cm long, or rarely with a well-developed leaf, each subsequent node with a bladeless sheath, first internode 2–3.3 cm long, peduncle 0–1.8 cm long, hirtellous. Main florescence 6.7–16 cm long, with 10–25 ± distichous bracts, widely spreading at anthesis, first internode 0.6–1.1 cm long, peduncle 0.8–1.3 cm long; lowermost bract 3.1–3.9 × 1.3–1.6 cm, pale green, chartaceous, glabrous or slightly puberulent to hirtellous at apex and along the margins; first prophyll 17–22 mm long, glabrous, ecarinate, interphylls rarely present, first one ca 23 mm long; bracteoles absent. Flowers 4–6 per bract; pedicel 1.5–2 mm long; ovary 2.5–4 mm long, hirtellous to puberulent at apex or glabrous; sepals 8.5–12 × 2–2.5 mm; corolla tube 27–33 × ca 2 mm, white, outside glabrous, inside hirsute except for a glabrous basal portion, lobes 7–9 × 4–5 mm, pale green; staminodes and stamen basally white, apically pinkish; outer staminode 9– 10 × 4.5–5 mm, spathulate, emarginate; stamen 5.5–7 mm long, appendage exceeding the base of theca by ca 0.5 mm, theca 1.5–2.5 mm long; callose staminode 7–8 × 6.5–7.5 mm, 0.5–1.0 mm petaloid apically, with a shelf-shaped callus at ca 4 mm from apex; cucullate staminode 6–6.5 mm long, lateral appendage ca 2 mm long; style 6–6.5 mm long (tripped). Capsule 15–17 × 3.5–5 mm; seed 13–15 × ca 3.5 mm; aril 2.5–3.5 mm long, with two flattened unilateral lobes.

Distribution and habitat:—Known from white sand areas in the lowlands around Manaus in Brazil; partly disturbed primary forests on well drained ground.

Discussion:— Monotagma breviscapum is easily recognized by its trailing rhizomes and very short synflorescence peduncle. It is most similar to M. vaginatum , from which it differs by the very short synflorescence peduncle, the presence of proper petioles (vs. absence), and the exannulate pulvini (vs. annulate).

Paratypes:— BRAZIL. Amazonas : ca 12 km E of Rio Preto da Eva, March 1986, Andersson & Hagberg 1757 ( GB, INPA, S); Rio Tupana, km 160 on road Manaus–Porto Velho, March 1974, Campbell et al. P 20839

(GB, INPA, MG); Reserva Forestal Ducke, km 27 on road Manaus–Itacoatiara, January 1971, Kennedy 106 ( DUKE, INPA) ; February 1971, Kennedy 840 ( RB) ; April 1971, Prance et al. 11285 ( F, GB, INPA, K, L, MG, NY, P) ; February 1981, Renner 145 ( US) .

Figures

FIGURE 1. Monotagma isotypes at GB. A, M. grallatum subsp. grallatum; B, M. grallatum subsp. subcentricifolium; C, M. lilacinum; D, M. breviscapum.