Marantochloa alba A. C. Ley, 2012

Ley, Alexandra C. & Classen-Bockhoff, Regine, 2012, Five new species of Marantaceae endemic to Gabon, Adansonia (3) 34 (1), pp. 37-52 : 38-41

Marantochloa alba A. C. Ley , sp. nov.

( Figs 1 ; 2 )

Marantochloa purpurea (Ridley) Milne-Redh. similis sed foliis homotropis, laminis inferioribus non albis, rhachidi inflorescentiae viridi et floribus albis praecipue differt, atque in silva haud in palude habitat.

TYPUS. — Gabon. Monts de Cristal , Tchimbele, in primary forest north of storage lake, 0°37’30.8”N, 10°24’16.7”E, 15.XII.2005, A. C. Ley 242 (holo- WAG!; iso- LBV!) .

PARATYPI. — Gabon. Monts de Cristal , in the closed forest around the hydroelectrical station in Tchimbele, 0°37’11.0”N, 10°24’24.1”E, 18.XII.2005, A. C. Ley 250 ( LBV, WAG) , 28.XI.2006, A. C. Ley 268 ( LVB, WAG) .— near Tchimbele , 0°36’S, 10°23’E, 1994, Breteler 13036 ( LBV, WAG) . — SEEF Logging Concession , 590 m, 0°27.597’N, 10°30.359’E, 21.X.2010, T. Stevart 3504 ( BRLU) . — 580 m, 0°27.914’N, 10°30.229’E, 23.X.2010, T. Stevart 3548 ( BRLU) .

HABITAT AND DISTRIBUTION. — Primary forest at around 500 m altitude in Monts de Cristal, Gabon (Fig. 3).

FIG. 3. — Collection sites of the five new species from Gabon. Site names: ■, Monts de Cristal/Kingele/Lonmin; Â, Mikongo, Monts de Cristal; ◆, Ndjole; ●, La Lope, research station; Ê, Mikongo, Lopé National Park.

DESCRIPTION

Rhizomatous herb, up to 2.5 m tall, forming clusters; above ground shoots ramified (branched) with five sheaths at the base.Leaves homotropic; leaf sheath up to 15 cm long, oblong-elliptic, pubescent on exterior side; petiole absent; pulvinus 5-10 cm, pubescent; lamina up to 27 × 12 cm, glabrous except at the base around the midrib, leaf ending in a tip 1.7 cm long. Inflorescence lax, hanging, rarely branching, up to 25 cm long; peduncle 6.5 cm long, green, pubescent; internodes of the inflorescence axis up to five, 2.0- 5.5 cm long, green, glabrous except of the base; fertile bracts distichous, 4-5 bracts per partial inflorescence (partial inflorescence) all of similar length (3.6 cm), green, glabrous except of the ciliate margin; flower pairs 1-2 (3)per bract; axis of flower pair 32 mm long, white, glabrous; pedicelles 3 and 13 mm long, rose, glabrous; bracteoles absent.Flowers white; sepals 15 × 5 mm; petals 22 × 6 mm, folded backwards; outer staminodes 25 mm long; cucullate staminodes about 20 mm long with yellow trigger appendage; callose staminode about 15 mm long, with characteristic upward bending near the base of the corolla tube (as found in M. purpurea (Ridley) Milne-Redh. and M. mannii (Benth.)Milne-Redh. );stamen 3 mm; petaloid appendage yellow, up to 20 mm long enfolding the cucullate staminode; style about 23 mm; ovary 2 × 1.5 mm, white pubescent. Fruit and seeds not seen.

REMARKS

Marantochloa alba A. C. Ley , sp. nov. differs from the similar Marantochloa purpurea in homotropic leaves, the colour of inflorescence and flower and the colour of the lower leaf side. In contrast to Marantochloa purpurea , which is restricted to swampy habitats Marantochloa alba A. C. Ley , sp. nov. has been found on dry ground in the primary forest.

Figures

FIG. 1. — A-C, Hypselodelphys lopei A. C. Ley, sp. nov., inflorescence (A), flower (B) and fruit (C); D, E, Marantochloa montsdecristalii A. C. Ley,sp. nov., inflorescence (D) and flower (E); F-H, Marantochloa alba A. C. Ley,sp.nov., flower pair (F), habitus (G), inflorescence (H); I, J, Thaumatococcus flavus A. C. Ley, sp. nov., habitus (I), inflorescence (J); K-M, Marantochloa grandiflora A. C. Ley, sp. nov., habitus (K), inflorescence (L) and flower pair (M). Scale bars: 1 cm.

FIG. 2. — Marantochloa alba A. C. Ley, sp. nov.: A, habitus with hanging, lax inflorescence (infl); B, leaf, oblong-elliptic; C, flower. A-C, A. C. Ley 242. Abbreviations: fs, fleshy staminode; o, ovary; os, outer staminode; p, petal; pa, petaloid appendage of fertile theca; s, sepal. Scale bars: A, 10 cm; B, C, 1 cm.