Jubaeopsis Becc., Webbia 4: 171 (1913)

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Content

Distribution

Map uses TDWG level 3 distributions (https://github.com/tdwg/wgsrpd)
Cape Provinces present (World Checklist of Arecaceae)B
KwaZulu-Natal present (World Checklist of Arecaceae)B
One species confined to the coastal reaches of two rivers in South Africa. (Dransfield, J., Uhl, N., Asmussen, C., Baker, W.J., Harley, M. & Lewis, C. 2008: Genera Palmarum. The evolution and classification of palms)A

Discussion

  • Jubaeopsis is the only member of Attaleinae in Africa,remarkable for its dichotomous stems and high chromosomenumber. (Dransfield, J., Uhl, N., Asmussen, C., Baker, W.J., Harley, M. & Lewis, C. 2008: Genera Palmarum. The evolution and classification of palms)A

Diagnosis

  • Clustering palm with short erect stems that frequently branch dichotomously, native to southeastern South Africa, staminate flowers with 7–16 stamens. (Dransfield, J., Uhl, N., Asmussen, C., Baker, W.J., Harley, M. & Lewis, C. 2008: Genera Palmarum. The evolution and classification of palms)A

Biology And Ecology

  • Jubaeopsis caffra grows gregariously on the steep north, rocky banks of the rivers, near sea-level. (Dransfield, J., Uhl, N., Asmussen, C., Baker, W.J., Harley, M. & Lewis, C. 2008: Genera Palmarum. The evolution and classification of palms)A

Etymology

  • Derived from the palm generic name Jubaea and -opsis — similar to, in reference to the similarities in floral and fruit structure. (Dransfield, J., Uhl, N., Asmussen, C., Baker, W.J., Harley, M. & Lewis, C. 2008: Genera Palmarum. The evolution and classification of palms)A

Common Name

  • Pondoland palm. (Dransfield, J., Uhl, N., Asmussen, C., Baker, W.J., Harley, M. & Lewis, C. 2008: Genera Palmarum. The evolution and classification of palms)A

Uses

  • The endosperm may be eaten. Because of its rarity, Jubaeopsis caffra is sought after as a collector’s item. (Dransfield, J., Uhl, N., Asmussen, C., Baker, W.J., Harley, M. & Lewis, C. 2008: Genera Palmarum. The evolution and classification of palms)A

Description

  • Moderate, clustered, unarmed, pleonanthic, monoecious palm. Stems erect, branching at the base and also aerially by forking, bearing leaf sheath remains distally, eventually becoming bare, marked with close leaf scars. Leaves pinnate, arranged in 5 vertical rows, marcescent or neatly abscising; sheaths tubular, soon disintegrating into an interwoven mass of fibres; apparent petiole short to elongate, adaxially channelled, abaxially rounded, glabrous, the margins bearing the remains of leaf sheath fibres, or becoming smooth; rachis ± straight or curved, adaxially channelled near the base, angled distally, abaxially rounded or flattened; leaflets numerous, single-fold, close, regularly arranged, except at the very tip, stiff, held in one plane, linear, the tips mostly asymmetrically 2-lobed, except at the leaf tip where acute or sometimes hooked, thinly glaucous, adaxial surface bearing scattered, minute, dot-like scales, abaxially with scattered dot-like scales, and a few large brown ramenta along the main vein, transverse veinlets conspicuous, sinuous. Inflorescences solitary, interfoliar, branching to 1 order, shorter than the leaves, protandrous; peduncle elongate, round in cross-section; prophyll short, tubular, 2-keeled, enclosed within the leaf sheaths, splitting apically; peduncular bract inserted near the prophyll, tubular and entirely enclosing the inflorescence until shortly before anthesis, later splitting longitudinally along the abaxial face and expanding, becoming cowl-like, woody, smooth, abaxially somewhat striate but not grooved, apically with a short, laterally flattened beak; rachis usually shorter than the peduncle, bearing numerous, spirally arranged, rather distant, spreading rachillae, each subtended by a low triangular bract; rachillae elongate, swollen at the very base and with a short or long basal bare portion, above which bearing few to numerous spirally arranged triads, Distribution of Jubaeopsis distally bearing paired or solitary staminate flowers; rachilla bracts and floral bracteoles small, inconspicuous. Staminate flowers rather large, perforate and micro-channelled, or perforate-rugulate, aperture margin asymmetrical, sessile; sepals 3, distinct, unequal, imbricate, ± triangular, similar; infratectum columellate; longest axis 63–81 µm [1/1]. Pistillate keeled; petals 3, distinct, very unequal, much larger than the sepals, flowers ovoid, only slightly larger than the staminate; sepals 3, distinct, boat-shaped with triangular tips, valvate; stamens (7–)8–16, filaments broad, rounded, with pointed tips, imbricate, somewhat irregularly slender, fleshy, ± cylindrical, apically inflexed, anthers linear, basally keeled; petals 3, distinct, ± twice as long as the sepals, broad, rounded, sagittate, dorsifixed, introrse; pistillode small, irregularly trifid. Pollen imbricate except at the short valvate triangular tips; staminodal ring ellipsoidal, frequently elongate, usually with either slight or obvious collar-like, very briefly toothed or consisting of several irregular tooth-asymmetry; aperture a distal sulcus; ectexine tectate, finely perforate, like lobes; gynoecium ± ovoid, trilocular, triovulate, stigmas 3, very short, ± triangular, ovules hemianatropous, laterally attached. Fruit 1-seeded, brown at maturity, globose with a short apical beak, stigmatic remains apical; epicarp smooth, mesocarp thin, fibrous, only slightly fleshy, easily separated from the endocarp at maturity, endocarp thick, bony, with 3 vertical grooves, the pores lateral just below the equator. Seed basally attached, somewhat irregular in shape, endosperm homogeneous with a large central cavity; embryo lateral, next to one of the endocarp pores. Germination remote tubular; eophyll entire, lanceolate. Cytology: 2n = 160–200. (Dransfield, J., Uhl, N., Asmussen, C., Baker, W.J., Harley, M. & Lewis, C. 2008: Genera Palmarum. The evolution and classification of palms)A

Anatomy

  • Root (Seubert 1998a, 1998b). See Robertson (1976a) for anatomy and development of fruit and seed. (Dransfield, J., Uhl, N., Asmussen, C., Baker, W.J., Harley, M. & Lewis, C. 2008: Genera Palmarum. The evolution and classification of palms)A

Fossil record

  • No generic records found. (Dransfield, J., Uhl, N., Asmussen, C., Baker, W.J., Harley, M. & Lewis, C. 2008: Genera Palmarum. The evolution and classification of palms)A

Relationships

  • Jubaeopsis is sister to all other members of the Attaleinae except Beccariophoenix (Asmussen et al. 2006, Baker et al. in review). (Dransfield, J., Uhl, N., Asmussen, C., Baker, W.J., Harley, M. & Lewis, C. 2008: Genera Palmarum. The evolution and classification of palms)A

Taxonomic accounts

  • For a discussion of morphology seeRobertson (1976b). See also Beccari (1913a) and Glassman(1987). (Dransfield, J., Uhl, N., Asmussen, C., Baker, W.J., Harley, M. & Lewis, C. 2008: Genera Palmarum. The evolution and classification of palms)A

Bibliography

    A. Dransfield, J., Uhl, N., Asmussen, C., Baker, W.J., Harley, M. & Lewis, C. 2008: Genera Palmarum. The evolution and classification of palms
    B. World Checklist of Arecaceae