Bismarckia Hildebr. & H.Wendl., Bot. Zeitung (Berlin) 39: 93 (1881)

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Number of Taxa

  • 1 species

Discussion

Biology And Ecology

Etymology

Diagnosis

Description

  • Robust, solitary, unarmed, pleonanthic, dioecious, tree palm. Stem erect, irregularly ringed with close leaf scars, becoming swollen basally. Leaves induplicate, costapalmate, marcescent in immature individuals, neatly abscising under their own weight in mature trunked individuals; sheath laterally ridged at the base, with a conspicuous triangular cleft below the petiole, with rows of scales in patches, petiole robust, adaxially channelled near the base, distally ± flattened, abaxially rounded, the surfaces greyish white, densely covered in white wax and patches of reddish, fringed caducous scales, the margins smooth; adaxial hastula often very large, distinctly lopsided, abaxial hastula absent; blade divided to ca. 1/4–1/3 its length along adaxial folds into regular, stiff, single-fold segments, these further shortly bifid, interfold filaments conspicuous, surfaces obscurely striate, densely covered with wax, and along the folds with caducous scales, transverse veinlets not visible. Inflorescence interfoliar, solitary, shorter than the leaves, the staminate and pistillate similar; peduncle ± rounded in cross-section; prophyll short, 2-keeled, included in subtending sheath; peduncular bracts several, tubular, rather loosely sheathing, with a broad, split triangular limb, sometimes strongly keeled, and covered with caducous scales and wax; rachis longer than the peduncle; rachis bracts like the peduncular, decreasing in size distally; first-order branches crescent-shaped in cross-section, longer than the subtending bract, not bearing a prophyll, branching at the tip to produce a group of 3–7 radiating, catkin-like rachillae, the group sometimes reduced to 1; staminate rachillae usually more numerous than the pistillate, slightly sinuous, bearing a tight spiral of rounded, densely hairy, striate bracts, connate laterally and partially adnate to the axis to produce pits, densely filled with hairs, pistillate rachillae usually more massive than the staminate, each bract subtending a solitary flower. Staminate flowers borne in a cincinnus of 3, embedded in the hairs, one flower emerging at a time, each bearing a membranous bracteole; calyx tubular, membranous, with 3 short, rather irregular lobes distally; corolla with a stalk-like base almost as long as the calyx lobes, bearing at its tip 3 ovate, hooded, valvate lobes; stamens 6, borne at the base of the corolla lobes, the filaments elongate, briefly united at the base, gradually tapering, anthers medifixed, versatile, latrorse; pistillode short, conical. Pollen ellipsoidal and ± bi-symmetric; aperture a distal sulcus; ectexine tectate, coarsely perforate-rugulate, aperture margin slightly finer; infratectum columellate; longest axis 35–46 µm; post-meiotic tetrads usually tetrahedral, rarely tetragonal or rhomboidal [1/1]. Pistillate flowers solitary, borne on a short hairy pedicel, the pedicel greatly elongating in fruit; sepals 3, imbricate, rounded, briefly connate basally; petals smaller than the sepals, 3, triangular, briefly connate at the base; staminodes united by their flattened triangular filaments to form a ring with 6 teeth, tipped with flattened empty, sagittate anthers; gynoecium tricarpellate, rounded, tipped with 3 low, slightly reflexed stigmas, septal nectaries present, ovule orthotropous with 2 lateral bodies, attached adaxially at the base. Fruit usually developing from 1 carpel, ± ellipsoidal, ovoid or rounded, the stigmatic remains and abortive carpels basal, the abortive carpels often enlarging to form 2 swellings; epicarp smooth, shiny, rich brown, somewhat speckled with lighter brown, mesocarp fibrous, ± aromatic, endocarp thick, irregularly flanged and pitted, and with a conspicuous central intrusion at the base. Seed basally attached, endosperm homogeneous, but grooved to match the endocarp intrusions; embryo apical. Germination remote-tubular; eophyll simple, strap-shaped. Cytology: 2n = 36. (J. Dransfield, N. Uhl, C. Asmussen, W.J. Baker, M. Harley and C. Lewis. 2008)

Anatomy

Relationships

Taxonomic accounts

Uses

Bibliography

  • Dransfield, J. , Uhl, N. , Asmussen, C. , Baker, W.J. , Harley, M. & Lewis, C. 2008. Genera Palmarum. The evolution and classification of palms. Kew Publishing, Royal Botanic Gardens Kew.