Dypsis onilahensis (Jum. & H.Perrier) Beentje & J.Dransf., Palms Madagascar : 207 (1995)

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Introduction

  • A handsome, medium-sized clustering palm which would do well in cultivation in the drier tropics. The species name comes from the Onilahy River, south of Toliara. (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
NW and W Madagascar and South-Central Madagascar. (J. Dransfield & H. Beentje, The Palms of Madagascar. 1995)A

Discussion

  • We are sinking C. brevinodis and C. midongensis as there are no distinguishing characters to separate these taxa from the bulk of D. onilahensis. Even the habitats seem to be identical. The protologue of C. brevinodis mentions as one of the syntypes Humbert 19032: Analamera, Analabe R banks. We believe this is an error; in the Flore the number (with the same data) is cited as 19245; on the sheets of Humbert 19245 (with the same data) Perrier has written C. brevinodis Perrier states that the stems are sometimes branched. In the southern populations there is a gradual cline from north to south as regards leaflet length (decreasing) and number (increasing), and inflorescence parts lengths such as peduncle, prophyll, peduncular bract (all increasing). The type of D. onilahensis is from the middle of the range, and nicely intermediate.
    The name midongensis refers to an obscure hamlet in the Itremo Massif, rather than to the large town in the south-east; before HB had realized this, he went to the large town and searched for this taxon. Not surprisingly, he did not find it, but in a nice case of serendipity, he found D. prestoniana. D. acuminumis very close, only distinguished by being solitary; by its fewer leaflets (30) which are on the short side, and by the inflorescence which is branched to one order only (though the type has one bifurcate rachilla). This species is extraordinaly close to D. baronii, and only differs in the habitat, the absence of minute reddish glands on the leaflets (not always present in D. baronii), and the homogeneous endosperm; the ruminations in D. bar onii are difficult to see at times, being very small, and D. baronii has been found in sites which are really in D. onilahensis territory, such as the forest of Ambohitsaratelo. In the absence of fruit, several collections could not be identified as belonging to one or the other [Miandrivazo: NW of Ambohitsaratelo-Bebao, July 1974 (fl), Morat 4590 (P, TAN); idem, Nov. 1986 (fl., y.fr.), Dransfield et al. 6447 (K, P, TAN)] but since Dorr et al. 3532 from the same locality has ruminate endosperm, they are more likely to be D. baronii. This whole complex deserves further study. (J. Dransfield & H. Beentje, The Palms of Madagascar. 1995)A

Biology And Ecology

  • Riverine forest, alt. 50-300 m (in the North) or riverine to evergreen forest (remnants) at 750-2400 m (Mountains of the Centre-North; Centre-South). Humbert states the palm is abundant on the rocky banks at flood level of the Analabe River in the north. (J. Dransfield & H. Beentje, The Palms of Madagascar. 1995)A

Conservation

  • Vulnerable. Though the distribution area is fairly large, the habitat is prone to destruction by fire. Numbers are estimated at less than a thousand. The population in the Isalo National Park is well-protected, but numbers less than a few hundred individuals. (J. Dransfield & H. Beentje, The Palms of Madagascar. 1995)A

Common Name

  • Kindro (Antankarana); Sihara (Bara). (J. Dransfield & H. Beentje, The Palms of Madagascar. 1995)A

Uses

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

Description

  • Clustering palm in tufts of 3-10 (occasionally appearing as solitary, fide Humbert). STEMS 2-20 m high, 2.5-15 cm diam. (-30 cm, fide Perrier), distally stepped and ringed; internodes 0.3-20 cm, proximally grey, distally dark green, nodal scars 0.2-0.5 cm, white. LEAVES 5-7 in the crown, gracefully arching to half-pendulous; sheath 18-60 cm, 4.5-6 cm diam., open for about one third, abaxially dark grey-green, pale green to pale brown but nearly always with a white waxy bloom, distally reddish-pubescent but glabrescent, adaxially rich red-brown, without or with only slight ligules to 1.5 x 4 mm; petiole absent or up to 40 cm long, proximally 1.2-2.3 x 1-1.5 cm with an adaxial triangular swelling as a sheath lining extension, distally 1.3-1.7 x 0.6-1.6 cm, slightly channelled with sharp edges, glabrous or with reddish scales on both surfaces, dark green with flecks of dark brown; rachis 1-1.8 m long, proximally channelled, in mid-leaf keeled and 0.7-1.7 cm wide, with reddish scales or glabrous; leaflets 42-64 on each side of the rachis, regular, in one plane, opposite leaflets also in one plane (in Isalo) or at an angle of 90° (elsewhere), slightly pendulous, curving or stiff with only the distal part arching, dark green and hardly shiny adaxially, mat and glaucous abaxially, the proximal (22-) 38-106 x 0.2-2 cm (interval up to 19 cm), median 35-75 x 0.8-2.5 cm (interval 0.8-4 cm), distal 8-44 x 0.2-1.9 cm (the distal pair joined for up to 2 cm), main veins 1-5, rather faint with only the midrib adaxially prominent, adaxially with proximal or scattered red-brown rather large (6-30 mm) ramenta on the midrib, otherwise glabrous, apices long- atten-uate, bifid. INFLORESCENCE interfoliar or infrafoliar at anthesis, infrafoliar at the fruiting stage, curved with spreading rachillae, branched to 2 orders (once to 3 orders in Humbert 7025); peduncle 15-78 cm long, usually curving through 180°, proximally 0.6-4 x 0.4- 1.2 cm diam., distally 0.9-4 x 0.6-1.5 cm, with scattered scales or glabrous; prophyll 11-87 cm, borne at 3.5-45 cm above the base of the peduncle, 2-6 cm wide with narrow wings to 3 mm wide, split only at the apex for some 3 cm or open for up to 50%, yellow turning pale brown with scattered reddish scales distally; peduncular bract often quickly deciduous (in trees with long peduncles), inserted at 6-42 cm from the base of the peduncle, 18-55 cm long, beaked for 0.5-4 cm, splitting completely (except for the beak), adaxially glabrous and redbrown, abaxially pale green with scattered red-brown laciniate scales; non-tubular peduncular bracts usually two near the peduncle apex, 0.2-2.5 x 0.5 cm; rachis 16-40 cm long, waxy pale green, with 5-15 branched and 8-12 unbranched first order branches, the most proximal with a rachis of up to 7.5 (-26.5 in Humbert 18432) cm and 0.8-1.7 x 0.3-0.5 cm proximally, with 4-12 rachillae; rachis bracts up to 1 cm; rachillae 6-30 cm long, sinuous distally, 1.5-4.5 mm diam., glabrous, with distant triads in slight pits with an acute triangular rachilla bract 1-1.5 mm. STAMINATE FLOWERS creamy green or yellowish, with a sweet or unpleasant smell, with sepals 1.4-2.9 x 1.5-2.8 mm, concave, acute, keeled and gibbous; petals free or connate up to 1 mm, 2.2-4.2 x 1.5-3.4 mm, ovate and concave, acute; stamens 6, uniseriate or very vaguely biseriate (then with 0.1 mm difference in insertion and a callus between the filaments), filaments 1.2-3 mm long and thinly cylindrical, anthers 1.3-2.8 x 0.6-1.3 mm, dorsifixed, versatile, the locules parallel or proximally slightly divergent; pistillode 1-2.3 x 0.4-1.3 mm. PISTILLATE FLOWERS with sepals 2.2-3.1 x 2.2-3.2 mm, rounded; petals 2.5-3.5 x 2.5-4 mm; staminodes 0.3-1 mm; gynoecium 2.8-3.5 x 1.5-2.9 mm. FRUIT yellow, waxy?, ovoid to subglobose, 10-18 x 7-15 mm, the apex rounded; endocarp very fibrous with almost free fibres. SEED black, 9-17 x 6.5- 12 mm, ellipsoid with pointed base and rounded apex, and a small subbasal depression; endosperm homogeneous. EOPHYLL bifid. (J. Dransfield & H. Beentje, The Palms of Madagascar. 1995)A

Materials Examined

  • Antsiranana: Analamera, Analabe R banks, Jan. 1938 (fr.), Humbert 19245 (P, syntype of C. brevinodis). Ambilobe: upper Mananjeba basin, Aug. 1913 (fl., fr.), Perrier 15800 (P, syntype of C. brevinodis). Ambanja: Manongarivo, 1200 m, May 1909 (fl.), Perrier 12083 (P); Tsaratanana, upper Sambirano valley, Nov./Dec. 1937 (fr.), Humbert 18432 (P). Andapa: Mt Mainborondro, March 1949 (fr.), Humbert 23377 (K, P). ?Maevatanana: Tampoketsa d'Antongodrahoza, upper Betsiboka R, Sept. 1922 (fl.), Perrier 14839 (P). Ankazobe: Ikopa R, March 1920 (fr.), Decary 7556 (P). Ambatofinandrohana: E of Midongy de l'Ouest, Feb. 1919 (fr.), Perrier 12499 (P, type of C. midongensis). Ihosy: Isalo, Oct. 1924 (fl.), Perrier 16548 (P); idem, Oct. 1924 (bud), Humbert 2822 (P); idem, NW of Ranohira, July 1992 (buds), Beentje & Andriampaniry 4709 (BH, K, MO, P, TAN); idem (seedling), Beentje & Andriampaniry 4713 (K); idem, Feb. 1990 (fr.), B. Du Puy et al. MB 673 (K); SW of Ranohira, Feb. 1990 (y.fr.), Phillipson 3406 (K, MO, TAN); 22km NNE of Zazafotsy, Feb. 1992 (seed), Beentje & Andriampaniry 4586 (K); idem, Dec. 1992 (fl.), Beentje 4768 (K, MO, P, TAN). Benenitra: Mt Votaka near Benenitra, July 1910 (fl.), Perrier 12074 (P, type of C. onilahensis). Betroka: Vohipolaka, Nov. 1933 (fl.), Humbert 11653 bis (P). Betroka/Befotaka: Ivohibe Peak, Sept. 1921 (bud), Perrier 12079 (P). Amboasary Atsimo: Ivakoany Massif, W slopes, Dec. 1928 (fl.), Humbert 7025 (K, P) and Nov.-Dec. 1933 (fl., y.fr.), Humbert 12248 (P). Tolanaro: Beampingaratra Mts, Maloto R valley Oct./Nov. 1928 (fl.), Humbert 6283 (P); upstream from Mahamavo, Jan./Feb. 1934 (fr.), Humbert 13905 (K, P); Col du Vavara, Nov. 1928 (fl.), Humbert 6539 (K, P). (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