Juania Drude, Nachr. Königl. Ges. Wiss. Georg-Augusts-Univ. 1878: 40 (1878)

Primary tabs

http://media.e-taxonomy.eu/palmae/photos/palm_tc_105168_2.jpg

Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
Juan Fernández Is.present (World Checklist of Arecaceae)B
One species on Juan Fernandez Islands. (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)A

Discussion

  • Juania is threatened in its habitat by introduced goats.It has proved rather difficult to grow and remains very rareboth in the wild and in cultivation. (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)A

Diagnosis

  • Dioecious pinnate-leaved palm of Juan Fernandez Island off the coast of Chile. Similar to Ceroxylon and Oraniopsis but distinct in the combination of complete prophyll, distinct petals, consistently 6 stamens and the eccentrically subapical stigmatic remains. (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)A

Biology And Ecology

  • Occurring on steep slopes and ridges in lower andupper montane forest at altitudes of 200–800 m above sealevel, most abundant above 500 m. (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)A

Common Name

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

Etymology

  • Named for the island of Juan Fernandez. (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)A

Uses

  • The apex is edible. In the past, the wood was used for walking sticks, cabinet work, and carvings. (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)A

Description

  • Solitary, moderate, unarmed, pleonanthic, dioecious palm. Stem stout, leaf scars oblique, internodes shorter above middle and very short at the crown, green, very smooth, with slight bloom. Leaves reduplicately pinnate, erect at first, then spreading; sheath fibrous, splitting opposite the petiole, not forming a crownshaft, covered with scaly tomentum when young; petiole much shorter than the rachis, channelled adaxially, rounded abaxially, with small brown scales; rachis triangular in cross-section, ridged adaxially, slightly rounded abaxially; leaflets narrow, single-fold, relatively short, bifid at tips, stiff, smooth, midribs more prominent adaxially, transverse veinlets not evident. Inflorescences interfoliar, solitary, usually 2 developed each year, the remainder aborting, branched to 2 orders at least proximally; peduncle elongate; prophyll short, tubular, laterally keeled, flat, open apically; peduncular bracts 3, similar to the prophyll, the second the largest and enclosing the third in bud, both the second and third larger than and inserted at some distance above the prophyll and first bract, all tubular and ± dorsiventrally compressed in bud, splitting abaxially at anthesis, becoming pendulous, persistent in fruit and at length marcescent; rachis elongate, longer than the peduncle, bearing numerous, spirally arranged branches, those at the base once-branched into short stiff rachillae, distal branches less divided or undivided, each branch and rachilla subtended by a small, sometimes adnate bract, bracts often lacking distally. Flowers white, solitary, open from early in development, briefly pedicellate, the pedicel subtended by an acute bract, the individual flowers usually with a bracteole on the pedicel. Staminate flowers with 3 sepals, united in a 3-lobed cupule, the lobes acute, about as long as to longer than the tube; petals 3, distinct, ± asymmetrical, ovate-acute, imbricate basally, separated above and shorter than the stamens in bud and at anthesis; stamens 6, the filaments distinct, anthers basifixed, versatile, emarginate to bifid apically, sagittate but the locules not divergent basally, latrorse; pistillode minute, ovoid, with trifid apex. Pollen ellipsoidal, asymmetric; aperture a distal sulcus; ectexine tectate, perforate-rugulate, aperture margin broad scabrate and finely perforate; infratectum columellate; longest axis ranging from 33–40 µm [1/1]. Pistillate flowers with 3 sepals, united in a 3-lobed cupule, the lobes, or some of them, as long as the tube; petals 3, distinct, imbricate basally and separated above in bud and in flower; staminodes 6, awl-shaped, distinct, lacking abortive anthers; gynoecium ovoid-attenuate, trilocular with 3 ovules, only 1 normally maturing, stigmas 3, short, recurved, ovules pendulous, hemianatropous. Fruit globose or nearly so, orange-red at maturity with eccentrically subapical stigmatic remains; epicarp smooth, mesocarp succulent and ± orange, with a few, flat, longitudinal, unbranched, whitish fibres adjacent to the very thin, cartilaginous endocarp, this adherent to the seed. Seed globose with mostly simple or forked vascular strands ascending from the base, endosperm homogeneous; embryo lateral in lower 1/3 or near the base. Germination adjacent-ligular; eophyll lanceolate, entire. Cytology not studied. (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)A

Anatomy

  • Leaf, stem (Tomlinson 1969), root (Seubert 1996b)and flowers (Uhl 1969b). Single phloem strands in largevascular bundles of the petiole. Patterns of floral vasculatureare similar to those of Ravenea and Ceroxylon (Uhl 1969b). (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)A

Fossil record

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

Relationships

  • For relationships, see Ceroxylon. (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)A

Taxonomic accounts

  • Moore (1969e). (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)A

Bibliography

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