Dypsis mirabilis J.Dransf., Palms Madagascar : 345 (1995)

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Introduction

  • There is nothing particularly unusual about the vegetative morphology of this species. It is a single-stemmed palm of the undergrowth of moderate size, with leaves that are divided into few broad leaflets, a habit common among undergrowth dypsids. The species name means wonderful, which may seem inappropriate for a rather ordinary looking palm. However, this species has most unusual staminodes in the staminate flower, and it is this rather obscure feature that caused us wonder. (J. Dransfield & H. Beentje, The Palms of Madagascar. 1995)A

Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
Madagascarpresent (World Checklist of Arecaceae)B
Marojejy and environs. (J. Dransfield & H. Beentje, The Palms of Madagascar. 1995)A

Discussion

  • The antesepalous stamens have didymous anthers (unusual among species with three stamens where, if the stamens are antesepalous, they are usually sagittate), but the most unusual feature is that there are three well developed staminodes that are adnate by their filaments to the pistillode, thus forming a large pyramidal body in the centre of the flower. The relationships of this species are obscure. Beentje & Andriampaniry 4687 has very young flower buds; nevertheless, three large antesepalous stamens and three minute central fused staminodes are visible. It is possible that Casimir 11731 (K, P) from Maroambihy, Sambava, also belongs here; inflorescence structure and vegetative features are similar, but no staminate flowers are available to confirm the identity. (J. Dransfield & H. Beentje, The Palms of Madagascar. 1995)A

Diagnosis

  • palma solitaria, folio foliolis paucis latis, inflorescentia 2-ramosa, rachillis pendulis, inter species floribus staminatis triandris staminibus antesepalis, staminodiis antepetalis ad pistillodium adnatis distincta. (J. Dransfield & H. Beentje, The Palms of Madagascar. 1995)A

Biology And Ecology

  • Lowland forest in valley bottoms; 90-200 m. (J. Dransfield & H. Beentje, The Palms of Madagascar. 1995)A

Conservation

  • Probably endangered. The distribution area is very small, and numbers are thought to be very low. (J. Dransfield & H. Beentje, The Palms of Madagascar. 1995)A

Common Name

  • Not recorded. (J. Dransfield & H. Beentje, The Palms of Madagascar. 1995)A

Uses

  • Not recorded. (J. Dransfield & H. Beentje, The Palms of Madagascar. 1995)A

Description

  • Solitary undergrowth palm. STEM to 2.5 m tall, to 15 mm diam., internodes c. 40 mm long. LEAVES c. 7 in crown; sheath 24 cm long, c. 25 mm diam., longitudinally striate, sparsely scaly, the sheath mouth with an irregularly tattering brown membranous margin; petiole c. 11 cm, adaxially channelled, abaxially ± rounded, covered with abundant caducous dark brown scales; rachis c. 85 cm; blade irregularly divided into 3-4 broad long acuminate leaflets on each side of the rachis, basal leaflets c. 80 x 11 cm, mid-leaf leaflets 70 x 4-7 cm, apical leaflets 52 x 7-8.5 cm, shallowly lobed distally, leaflet texture rather thin in dried specimens, glabrous, short transverse veinlets evident. INFLORESCENCE interfoliar, branching to 2 orders, to c. 115 cm long; peduncle 45 cm long, densely covered with dark red indumentum; prophyll and peduncular bract lacking in available material; rachis c. 70 cm long, covered with indumentum as the peduncle; rachillae ± pendulous, very numerous (c. 100), 12-16 cm long, c. 2 mm diam., glabrous, tending to be narrow just above the triad insertion, triads 1-3 mm apart, rachilla bract c. 0.5 x 2 mm. STAMINATE FLOWERS at anthesis rounded, orange, c. 1.8 mm diam.; sepals 1.0 x 0.9 mm, apically erose, keeled; petals rounded triangular, 1.5 x 1.3 mm, striate; stamens 3, antesepalous, emerging slightly between the petals at anthesis, filaments terete, 1.1 mm long, c. 0.5 mm wide at base, tapering to 0.3 mm wide at tip, anthers didymous, 0.4 x 0.1 mm; staminodes antepetalous, filaments adnate to the central pyramidal pistillode forming a composite structure c. 1.1 x 0.7 mm, the filaments c. 1.1 x 0.2 mm, free at the very tip, empty anthers c. 0.1 x 0.1 mm, free pistillode c. 0.1 mm high. PISTILLATE FLOWERS known only in very immature bud; sepals in fruit triangular, c. 1 x 1 mm; petals in fruit triangular, striate, c. 2 x 2 mm; staminodes 6. Immature FRUIT ovoid, green, 12 x 7 mm; endocarp composed of brown fibres. SEED 9 x 5 mm; endosperm homogeneous. (J. Dransfield & H. Beentje, The Palms of Madagascar. 1995)A

Materials Examined

  • Andapa: Marojejy, Mandena, headwaters of Bangouabe, east of Jean Poste Juvance, Nov. 1989 (fl., fr.), Dransfield JD6771 (holotype K; isotype TAN); 6 km SW of Ambodivoara, Ankatoka River valley, June 1992 (fl. buds), Beentje & Andriampaniry 4687 (K, MO, P, TAN). (J. Dransfield & H. Beentje, The Palms of Madagascar. 1995)A

Bibliography

A. J. Dransfield & H. Beentje, The Palms of Madagascar. 1995
B. World Checklist of Arecaceae