Arecaceae
Calamus

Calamus essigii W.J.Baker

First published in Kew Bull. 57: 720 (2002)
This species is accepted
The native range of this species is SE. New Guinea. It is a liana and grows primarily in the wet tropical biome.

Descriptions

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation
Predicted extinction risk: threatened. Confidence: low confidence
[AERP]

Vernacular
Hulawarra (Goari)
Distribution
Known from a small area between the Astrolabe Range and the Tinumu Range due east of Port Moresby
Conservation
Near threatened. While the forests of the Astrolabe and Tinimu Range are thought to be relatively undisturbed, C. essigii is known from an area so small and in such close proximity to the major urban centre of Port Moresby that the species faces an appreciable level of threat
Diagnostic
C. anomaloBurret affinis sed habitu graciliore, petiolo distincto ferenti, foliolis angustissimis linearibusque, et inflorescentia ramis paucioribus differt
Biology
In under storey of lower montane forest with Lithocarpus and Castanopsis between 650 and 900 m
General Description
Very slender, clustering, short-stemmed rattan, sometimes climbing to 8 m. Stem with sheaths 4 – 5 mm diam., without sheaths 2 – 2.5 mm diam.; internodes 4.5 – 10 cm. Leaf ecirrate 12 – 23 cm long including petiole, to 29 cm in juvenile leaves on lower stem; sheath with thin, brown, scaly indumentum, most abundant near sheath mouth, scattered brown scales in lower sheath, unarmed or armed with numerous, very fine spines to 3 mm long, most abundant in upper parts of sheath, spines most numerous near to sheath mouth, spines at sheath mouth to 5mm long, erect; knee to 7 mm long, unarmed or armed as sheath; ocrea absent or minute; petiole 1 – 3 cm, to 11 cm in juvenile leaves on lower stem, to 2 mm wide and 1.5 mm thick at base, flattened adaxially, rounded abaxially, with thin, brown indumentum, unarmed or with few solitary, reflexed, grapnel spines; rachis 8 – 55 mm, with indumentum as petiole, unarmed or armed as petiole; leaflets 3 – 5 each side of rachis, subregular or in two distinct subregular groups, narrowly linear, longest leaflet near base 12 – 21.5 × 0.5 – 0.8 cm, apical leaflets 11.5 – 21 × 0.4 – 0.6 cm, apical leaflet pair united to one tenth of their length or not at all, few minute spines on leaflet margins, most frequent towards apex, very few on adaxial surface of midrib, transverse veinlets rather inconspicuous. Flagellum to 36 cm, readily detached. Staminate inflorescence 10.5 – 17.5 cm long including 15 – 45 mm peduncle, branched to 2 orders or rarely 1 order; prophyll 40 – 80 × 3 – 5 mm, tubular if not subtending primary branch, otherwise split to base by emerging primary branches, sometimes remaining tubular distally, with indumentum as sheath, sometimes armed with few reflexed grapnel spines; peduncular bracts absent; rachis bracts 20 – 60 × 3 – 4 mm, similar to prophyll, imbricate; primary branches up to 5, to 45 mm long, 25 – 35 mm apart, straight to strongly recurving, barely adnate to primary inflorescence axis above point of insertion, bursting through base of rachis bracts, with up to 6 rachillae, sparse to abundant brown indumentum on all axes, readily detached; rachillae 2 – 15 mm × 0.3 – 1 mm, sometimes recurving; rachilla bracts 0.75 – 1 × 0.6 – 1 mm, triangular, distichous, glabrous; floral bracteole 0.8 – 1.2 × 0.5 – 0.6 mm, elliptic. Staminate flowers 4 × 2 mm prior to anthesis; calyx 1.8 – 2 mm diam., tubular in basal 1 mm, with 3 lobes to 0.5 mm long, glabrous; corolla 3.5 × 1.5 mm in bud, very briefly tubular at base, glabrous; stamens 6, filaments 2 – 3 × 0.3 – 0.5 mm, anthers 1.5 × 0.4 – 0.7 mm; pistillode minute, to 1 mm long. Pistillate inflorescence similar to staminate inflorescence, 10 – 10.5 cm long including 30 – 40 mm peduncle, branched to 1 order; prophyll 25 – 50 × 2 – 5 mm; peduncular bracts absent or 1, similar to prophyll; rachis bracts 13 – 30 × 3 – 4 mm; primary branches (=rachillae) up to 5, 4 – 20 mm × 1 – 2 mm, 15 – 30 mm apart, recurving; rachilla bracts 0.5 × 1.5 mm, subdistichous, triangular, glabrous; proximal floral bracteole 1 × 0.5 mm, distal floral bracteole 1.2 – 1.7 × 1 – 1.5 mm, glabrous, scar of sterile staminate inconspicuous. Pistillate flowers 4 × 2 mm prior to anthesis; calyx 2 mm diam., tubular in basal 3 mm, with 3 lobes to 0.75 × 1.25 mm, glabrous; corolla 3 × 2 mm, tubular in basal 0.5 mm, with 3 lobes to 2.5 × 1.5 mm, glabrous; staminodes 6, 2 mm long, staminodal ring 0.5 mm high; ovary 1.5 × 1.5 mm, spherical, style 1 mm long, stigmas 1 mm long. Fruit globose, 9.5 × 9 mm including beak to 1 mm long, with 12 – 15 longitudinal rows of smooth scales with minutely fimbriate margins. Seed somewhat immature in available material, 7 × 5.5 × 5 mm, ellipsoid, with a shallow depression on one side; endosperm homogeneous; embryo basal.
[PW]

Sources

  • Angiosperm Extinction Risk Predictions v1

    • Angiosperm Threat Predictions
    • http://creativecommons.org/licenses/by/4.0

  • Herbarium Catalogue Specimens

    • Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/

  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0

  • Kew Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0

  • Palmweb - Palms of the World Online

    • Palmweb 2011. Palmweb: Palms of the World Online. Published on the internet http://www.palmweb.org. Accessed on 21/04/2013
    • Content licensed under Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License http://creativecommons.org/licenses/by-nc-sa/3.0