Chamaedorea robertii Hodel & N.W.Uhl, Principes 34: 120 (1990)

Primary tabs

no image available

Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
Costa Ricapresent (World Checklist of Arecaceae)B
Panamápresent (World Checklist of Arecaceae)B
PANAMA. Bocas del Toro. Chiriqui. Cocle. Veraguas. COSTA RICA. Alajuela. Heredia. Guanacaste. San Jose. (Hodel, D. 1992. Chamaedorea Palms, The Species and Their Cultivation. The International Palm Society.)A

Discussion

  • C. robertii is an attractive and unusual species due to its bifid, heavily nerved leaves, stemless habit, and spicate inflorescences. The flowerbearing portion of the staminate inflorescence is pendulous and densely crowded with relatively large, white-tinged-with-green flowers. The pistillate inflorescence has densely crowded, yellow flowers and attractive, burgundy-colored bracts sheathing the peduncle.
    Chamaedorea robertii is most closely related to C. pumila and C. sullivaniorum. Bluish or grayish iridescent green leaves with more closely toothed margins, branched staminate inflorescences with greenish-yellow flowers, and green pistillate flowers distinguish the latter two species. Also, C. robertii differs from C. pumila in the larger, broader leaves with more nerves (12-15 rather than 10) and from C. sullivaniorum in the more deeply bifid blade. C. robertii occurs in a few collections in California, Hawaii, and Australia. (Hodel, D. 1992. Chamaedorea Palms, The Species and Their Cultivation. The International Palm Society.)A

Biology And Ecology

Description

  • Habit: solitary, decumbent then shortly erect, to 1 m tall but often appearing stemless. Stem: 2.5 cm diam., creeping at or slightly below leaf litter, green, prominently ringed, internodes 1.5 cm long. Leaves: 5-7, erect-spreading, bifid; sheath to 12 cm long, splitting deeply opposite petiole, tubular only in basal 1/3 green, ragged and brown-margined apically; petiole 20-25 cm long, flattened and green above and slightly channeled from lower margins of blade extending downward to sheath, rounded and green below; rachis 20 cm long, angled and green above, rounded and green below; blade 40-50 x 20 cm, incised apically to nearly 1/2 its length, each lobe 20-25 cm long, rich green, tips 18-20 cm apart, acuminate, 12-16 raised and prominent primary nerves on each side of rachis, secondaries numerous and faint, margin conspicuously toothed. Inflorescences: infrafoliar or sometimes interfoliar, often emerging from the leaf litter of forest floor, spicate. Staminate with peduncle to 25 cm long, 5 mm wide at base and there ± flattened, 4 mm diam. at apex, erect-ascending, pale green or yellowish where exposed in flower; bracts 5, prophyll 2 cm long, 2nd bract 3-4 cm, 3rd 5 cm, 4th 12 cm, 5th 15 cm, acutea-cuminate, greenish at anthesis, ageing to dark brown or nearly black, tubular, especially upper ones inflated apically to 8 mm diam. For 2/3 their length, ± leathery, longitudinally striate-nerved, uppermost equalling or slightly exceeding peduncle, sometimes 5th bract very short and concealed by 4th one; rachis or fiowerbearing portion to 10-15 cm long, 3-4 mm diam., pendulous, whitish, longitudinally ridged around each flower. Pistillate ascending but often spreading in fruit; peduncle similar to that of staminate but orange in fruit; bracts 5, similar to those of staminate but burgundy in color when newly emerged, browning only slightly by anthesis, brownish in fruit; rachis to 10 cm long, ± stiff, horizontal, pale yellow or whitish in flower, 5 mm diam., orange in fruit. Flowers: Staminate in 3 dense spirals, closely placed but not contiguous, 5 x 3.5 mm, bullet-shaped, greenish, sunken in elliptic pits 3-4 mm long; calyx 1-1.25 x 3.5 mm, membranous, whitish tinged with green apically, shallowly lobed, sepals imbricate in basal 3/4, broadly rounded apically; petals 4 x 3 mm, valvate, free more than 1/2 to base, erect, acute, whitish basally; stamens exserted beyond petals, filaments 4 x 0.6 mm, columnar, clear-colored, anthers 1.25 mm long, bilobed, held beyond petals; pistillode 4 x 0.75 mm, columnar, clear-colored, 3-lobed apically. Pistillate densely arranged, some contiguous but most not, 11.5 mm distant, 2.5 x 3.5 mm, subhemispherical, yellow, sunken in circular depressions 4 mm across; calyx 1 x 3.5 mm, pale yellowish or whitish, very shallowly and inconspicuously lobed, sepals imbricate nearly to apex; petals 2.5 x 4.5-5 mm, imbricate nearly to apex, erect, truncate and mucronate apically; pistil 2.5 x 3-3.5 mm, strongly depressed-globose, pale yellowish, styles very short or lacking, stigma lobes erect, pointed. Fruits: 7 mm diam., globose, black, densely crowded. (Hodel, D. 1992. Chamaedorea Palms, The Species and Their Cultivation. The International Palm Society.)A

Materials Examined