Araceae Juss.

Dieffenbachia horichii Croat & Grayum

This species is accepted, and its native range is Costa Rica.


CATE Araceae, 17 Dec 2011.

It occurs in Pre- montane rain forest (P-rf) and transition forests be- tween Tropical wet forest (T-wf) and Premontane rain forest (P-rf) life zones (Holdridge, 1967).
General Description
Stout herb, 1-1.5(2) m tall; sap white, copious, foetid, caustic; stem erect on younger parts, to 1.2 m long and reclining on older parts, internodes 1- 3 cm long, 4-6 cm diam., semiglossy to glossy, dark green to medium green; petioles 8-33 cm long (av- eraging 18.7 cm long), weakly glossy, sheathing nearly or completely throughout; sheath medium green streaked with yellow-green, margins involute, the tip free-ending and irlequilaterally rounded-auriculate (auricle sometimes extending up to 1.5 cm beyond blade); unsheathed portion lacking or to 1.2 cm long (rarely to 6 cm long), obtusely somewhat flattened in cross section; blades narrowly to broadly elliptic to ovate-elliptic, 26-60 x 9-30 cm (averaging 45 x 19 cm), 1.9-3.4 times longer than wide (averaging 2.5 times longer), 1.7-4 times longer than petiole, slightly inequilateral, one side 0.5-1.2 cm wider than the other side, subcoriaceous to coriaceous, somewhat bicolorous, acuminate at apex, + equilateral and obtuse to rounded (rarely acute or narrowly rounded) at base, margins weakly undulate; upper surface dark green, semi- glossy to highly glossy, drying dark gray-green to dark yellow-brown; lower surface weakly glossy to matte, moderately paler, drying yellow-brown to yellowish green; midrib broadly and shallowly sunken to flat-sunken above, 5-20 mm diam., con- vex and bluntly low-triangular below, drying light brown to dark brown paler than surface below; primary lateral veins 14 to 21 per side, departing mid- rib at a mostly 30°-40° angle above middle, often 70°-90°, often arising at an acute angle, spreading to the margins, broadly curved toward apex, even- tually merging at margins, weakly sunken above, weakly convex below, drying brownish and darker than surface below; the interprimary veins usually darker than surface, 1 between each pair of primary lateral veins; minor veins visible, slightly darker than surface, drying moderately obscure on lower surface. INFLORESCENCES 3 to 6 per axil; peduncle 8.5-19 cm long (averaging 13.5 cm), 3-6 mm diam., drying striate; spathe 14.5-32.5 cm long, 4-5.5 cm diam. (averaging 20.8 cm long), 2.5-4 cm diam. at constriction, 0.9-2.3 times longer than the peduncle (averaging 1.5 times longer than the peduncle), gradually long-tapered toward apex from midway, light green to medium green throughout; spathe tube 3 x 2.3 cm diam. when furled (flattening 4.0-5.5 cm wide), the constricted area flattening 2.5-4.0 cm wide; spathe blade 2.5- 4 cm wide at anthesis; spadix 13-27 cm long (averaging 17.4 c m long); free portion 10-13.5 cm long; pistillate portion to (6.5)8-10.8 cm long (averaging 8.3 c m long), 8-17 mm wide, drying 8 mm diam.; fertile staminate portion 8. 3-12 cm long, crearm-coloured, moderately tapered toward apex and weakly tapered toward base, 7-12 mm diam. midway; mostly sterile intermediate segment 1 .7--3.7 cm long, with a few scattered staminodia throughout; pistils 4.-3 to 69, irregularly scattered, nearly contiguouse .-3 to 4(6 to 7) dispersed across spadix width separated from one another by up to 4 times their width; ovary depressed-globoxe 2 mm long, yellow-green; stigma cushion-shaped, 2.8-3.4 mm diam., about twice as wide ax thick and usually broader than the pistil at anthesix, yellowish; staminodia white, 3 to 5 per pistil, 3-4 mm long, free or briefly united at base; synandria 1.6-3.0 mm diam., subrounded, depressed medially at apex, drying orange-brown. INFRUCTESCENCE 19-24 cm long; spathe orange outside; spadix 8-15 cm long; berries red, subglobose, ovoid to ellipsoid, 7- 10 mm long.
Dieffenbachia horichii is known only from the Pacific slope of Costa Rica from the Carara reserve and Puriscal region to the San Isidro region and Dominical.
Dieffenbachia horichii begins to flower in the early rainy season from May to July but flowering collections have also been seen in September. Immature inflorescences have been seen from November to May, and mature fruits have been seen from the late rainy season (November) to early rainy season (late June).

Native to:

Costa Rica

Dieffenbachia horichii Croat & Grayum appears in other Kew resources:

Date Reference Identified As Barcode Type Status
Croat, T.B. [79115], Costa Rica K000400562 isotype
Croat, T.B. [79115], Costa Rica K000400563 isotype

First published in Ann. Missouri Bot. Gard. 91: 715 (2004)

Accepted by

  • Govaerts, R.H.A. (2011). World checklist of selected plant families published update Facilitated by the Trustees of the Royal Botanic Gardens, Kew.


CATE Araceae

  • Croat, T. 2004. Revision of Dieffenbachia (Araceae) of Mexico, Central America and the West Indies. Ann. Missouri Bot. Gard.. 91 (4): 668-772

  • CATE Araceae

    Haigh, A., Clark, B., Reynolds, L., Mayo, S.J., Croat, T.B., Lay, L., Boyce, P.C., Mora, M., Bogner, J., Sellaro, M., Wong, S.Y., Kostelac, C., Grayum, M.H., Keating, R.C., Ruckert, G., Naylor, M.F. and Hay, A., CATE Araceae, 17 Dec 2011.

  • Herbarium Catalogue Specimens

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  • Kew Backbone Distributions

    The International Plant Names Index and World Checklist of Selected Plant Families 2022. Published on the Internet at and
    © Copyright 2017 World Checklist of Selected Plant Families.

  • Kew Names and Taxonomic Backbone

    The International Plant Names Index and World Checklist of Selected Plant Families 2022. Published on the Internet at and
    © Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families.