Anthurium Dressleri is an exotic, bright, colorful petals that are certain to brighten up any room or office. It’s easy to care for, requiring only moderate temperature, light, and water. Its bold, pointed leaves make it a statement-making style choice for any modern interior.
Anthurium dressleri is the holy grail of Anthurium collections. This species has large, heart-shaped leaves that exhibit a deep, glossy purple emergent coloration. The leaves have a velvety texture and purple veining, adding to their allure.
The easiest way to identify Anthurium dressleri is by using its leaves. The leaves are heart-shaped, with well-defined lobes, sometimes overlapping each other.
The color is dark green, with a velvety texture and a slight shimmer. The frond is slightly more prominent than the other veins and is light green in color.
The leaves have long petioles with a purplish color on the bottom.
Unlike other Anthurium species, such as A. crystallinum or A. clarinervium, Anthurium dressleri does not have white leaf veins.
Why is it called “Anthurium Dressleri Croat”?
Anthurium dressleri takes its name from two famous botanists. First, it was named “dressleri” in honor of American botanist Robert Louis Dressler, who spent his life documenting and describing hundreds of plant species, mostly orchids.
The suffix “Croatian” is used in botanical nomenclature to refer to Thomas Croat, an American botanist and aroid expert who has so far collected more than 85,000 species.
in Panama, Anthurium dressleri Croat is currently understood to be restricted to a region whose western boundary is marked by the eastern edge of the Panama Canal, thence eastwards into the coastal and foothill forests on and in the vicinity of Cerro Bruja (Panama). It has been vouchered for the provinces of Colon and Panama, as well as the Canal Zone (Tropicos; Croat, 1986). Croat (1978) also reported several collections from Colombia, e.g. Giana 1702 collected at 150 m in Valle Department (CUYC), Kennedy 731 collected at Anchicaya in Valle Department (F), and Forero & Gentry 792 collected on Alto de Buey at 300-1,000 m in Colon Department (COL). Anthurium kunayalense Croat & Vannini is believed to be restricted to the Comarca de Kuna Yala (San Bias) and possibly the Pacific versant of the Colombian Colon (Galeano #4181; Croat and Vannini, 2010). Both species are apparently confined to the Caribbean versant in this country, and have been collected at elevations from near sea level to ca. 1,000 m (Correa et al., 2004; Croat & Vannini, 2010). In spite of tentative recent determinations (Croat & Vannini, 2010) the author believes that the Colombian material in toto warrants closer scrutiny with regard to these plants’ identities and distribution. There is a hiatus of more than 500 km to the south-southwest between the known Panamanian populations and the Colon records Over the past three decades, Anthurium dressleri Croat and A. kunayalense Croat & Vannini have been collected in the wild by a number of visiting and resident botanists and amateur plants men (Tropicos online; Comparison between young A. kunayalense Cleft) and A. dressleri (right).
Both plants are representative of type locality material. White, 1982; Croat, 1986; Dressler, pers. comm.; Carroll, pers. comm.). While many of these collections are concentrated from a handful of well-known localities (i.e. the forests along the upper RIO Guanche, Cerro Bruja, the Chepo-Cangandi Road, and the Llano-Carti Road), other herbarium accessions and reliable observations made at disparate sites provide us with a fairly clear picture of these species’ current distribution. The airline distance between the type locality of A. dressleri Croat located near Ponobelo, Colon Province and the type locality of A. kunayalense Croat & Vannini in Kuna Yala, Comarca de Kuna Yala is ca. 80 km. No clear evidence of hybridization between these two species has been found to date, although several herbarium specimens originating from Cerrro Bruja and recently examined by Croat have remarkably orbicular leaves and white spathes and may be intergrades. While documented collections and field observations suggest that these two species are allopatric, the proximity between known populations of A. dressleri in eastern Colon and A. kunayalense in western Kuna Yala (less than 40 km airline) suggests that they may be sympatric at some localities. From mid-2006 through late 2007, I had the opportunity to observe significant numbers (ca. 100) of mature wild Anthurium dressleri at several of the historically-documented localities. These include the forested slopes on the southern bank of the upper Rio Guanche, Colon Province (the type locality), the vicinity of the Portobelo-Palenque Road, Colon Province, and relictual forests in the vicinity of Cerro Santa Rita (the “Santa Rita Ridge” in lit.) , Colon Province. I have also observed a number of wild A. kunayalense at various locations in the forested parts of the Llano-Carti Road, Comarca de Kuna Yala. In addition, I am quite familiar with the Windswept elfin forest of the southwestern and northeastern slopes of Cerro Jefe near the summit, although I have not encountered either of the species during my hikes there and literature reports of a collection made at this locality may be in error (Dressler, pers. com.). The habitat at these sites ranged from lightly disturbed (upper Rio Guanche, parts of the Kuna Yala topotype) to severely degraded (Santa Rita). A particular locality for A. kunayalense that has often been referenced in literature (White, 1982; Croat, 1997) and is prevalent as a source for herbaria collections (Tropicos) at km 12.5 on the Llano-Carti, was largely obliterated in 2007 by an earthmoving equipment-caused landslide that occurred during the course of improving the road (this was also a prime locality to view a number of massive specimens of Philodendron gigas Croat). My own observations, coupled with fairly recent vegetational mapping, indicates that there remains a great deal of fairly inaccessible, largely undisturbed old-growth tropical wet forest scattered throughout these species’ known range in Panama (ANAM/CBMAP, 2000), particularly between Cerro Jefe and the Caribbean foothills of eastern Colon Province and western Comarca de Kuna Yala Province, that suggests that both species’ future in the wild is secure. For conservation planning purposes, in Panama Anthurium dressleri is documented from, and continues to inhabit, the following protected areas: Soberania National Park (Pipeline Road), Chagres National Park (south slope of Cerro Bruja), and Portobelo National Park (type locality and foothill Cerro Bruja collections). Anthurium kunayalense is recorded from the PEMASKY Nature Park (Kuna Yala Biosphere Reserve, Llano-Carti Road beyond the vicinity of Nusagandi) and may also occur in Chagres National Park (based on Cerro Jefe report). If either or both species is ever reliably reported from Panama’s Caribbean Darien Province in the Serrania del Darien and/or in the scattered sierras in the Comarca Embara, then it/they would also be nominally protected within the boundaries of Darien National Park.
Anthurium dressleri and A. kunayalense are terrestrial species that favor rocky outcrops or well-drained slopes in undisturbed or lightly-disturbed tropical wet, rain- and lower montane wet forests. They will also very occaSionally colonize fallen logs and decaying hardwood tree stumps. The vegetational map of Panama (ANAM/CBMAP, 2000) identifies these ecosystems as “Bosque perennifolio ombrofilo tropical latifoliado de tierras bajas” (Shady lowland tropical broadleaf evergreen forest) and “Bosque perennifolio ombrofilo tropical latffoliado submontano” (Shady premontane broadleaf evergreen forest). Plants are usually extenSively-rooted into the upper leaf litter layers that overlie rock or clay – often for more than 100 cm, rather than into the underlying substrate proper (pers. observ.). Conditions on the forest floor of these ecosystems are often quite dark with dappled sunlight, and are warm, very humid and still. Given their size and the impressive vegetational diversity in the forests that they inhabit, these species are fairly unobtrusive where they occur as isolates or in small groups, but can also be quite conspicuous in areas where they occur in larger colonies on ridge tops. The flora associated with both species is exceedingly difficult to characterize since it varies from locality to locality; all of the sites that I have visited (except the relictual populations near Cerro Santa Rita) contained very high palm (Palmae) diversity, particularly understory species from the genera: Geonoma Willd., Oenocmpus Mart., Attalea Kunth, Bactris Jacq. and Asterogyne H. Wendl. (Hubbuch & Craft, 1995; pers. observ.). Emergent palms associated with Anthurium dressleri and A. kunayalense include Socratea exorrhiza (Mart.) H. Wendl., Wettinia quinaria (O.F. Cook & Doyle) Burret, and Welfia regia H. Wendl. ex-Andre as well as mature trees from a number of families including Anacardiaceae, Fabaceae, Malvaceae, Rubiaceae and Bignoniaceae and Lecythidae. The terrestrial A. colonense Croat is also commonly sympatric with both species. Three endemic cycads, Zamia elegantissima Schutzman, Vovides & Adams, Z. cunaria Dressler & D. W. Stev., and Z. dressleri D. W. Stev. are rather frequently encountered in the general vicinity of A. dressleri and A. kunayalense colonies (pers. obs.). Rainfall measurements vary widely throughout this region. Historical records from a meteorological station at Portobelo located within less than five km of the type locality show that total precipitation can exceed 6,000 mm annually in exceptionally wet years, although the averages across the species’ Panamanian range appear to range between 3,000 and 4,000 mm annually (Cornthwaite, 1919; Panama Canal Co. meterological data in Ridgely, 1981; Correa et al., 2004). The region immediately east of the Canal Zone on the Caribbean versant witnesses no defined dry season, but does experience reduced precipitation evident in the months of February, September and October. Average annual temperatures oscillate between 25 and 27 degrees C. Upper elevation localities, such as summit regions of Cerro Bruja (979 m) and Cerro Jefe (1,007 m) are considerably cooler, with average annual temperatures closer to 20 degrees C.
The affinities of the Anthurium dressleri complex beyond Panama remain uncertain. They share a number of morphological characteristics with some members of the Anthurium splendidum Hort. ex Bull. complex from northwestern Colombia, such as bullate, matte-satiny-velvety leaves, abaxially ridged (winged) petioles and genicula, contrast-colored new growth, a terrestrialllithophytic lifestyle, and relatively compact size (Croat & Cirino, 2005).
From both phytogeographical and ecological perspectives (all inhabit shady locations in very wet to near pluvial ecosystems), it seems plausible to postulate that all these species are closely-related. Many of these shared characters, such as micro-papillate/velutinous leaf surfaces, coupled with quilted/bullate leaf lamina and pink-reddish-red anthocyanin-saturated new growth, are all adaptations to maximize capture of light in the forest understory at both visible spectra, as well as photosynthetically active radiation-PAR (Lee et al., 1979) and to facilitate rapid shedding of rainwater from the leaf lamina in perhumid environments. Not coincidentally, these characteristics have evolved independently in a number of plant families in Panama and elsewhere, and some observers have been struck by the degree of this convergence evident in ecosystems inhabited by A. dressleri and A. kunayalense (White, 1982).
While Anthurium dressleri plants in the wild normally exhibit short-erect stems to only 20-25 cm tall, careful excavation around the bases of some of these larger plants at the Rio Guanche population reveal thick, decumbent stems rooted in the leaf litter layer to 65-70 cm in length and ca. 4 cm in diameter. These dormant stems usually appeared healthy upon inspection, and small sections cut from the distal portions establish readily in cultivation. Even assuming that wild plants are capable of the optimal stem growth rates observed in cultivation, which appear to be on the order of ca. 15 mm elongation annually, at a minimum some of these individuals would be close to 50 yr of age. Based on my observations in cultivation, given the very slow growth of some members of this species and the maturity and stability of the ecosystem at the type locality, I suspect that the largest individuals that I have encountered are much older than this. Anthurium kunayalense is notably smaller overall and stems rarely exceed 20 em in length and 2.5 em in diameter (Croat & Vannini, 2010).
From both notes on specimens housed in herbaria and personal observation, it appears that Anthurium dressleri generally flowers during the northern hemisphere spring and early summer, with peak flowering in plants grown in Guatemala City, Guatemala (approximately five degrees north of Portobelo, Colon on the central Panamanian Caribbean coast) occurring during March-April. In my collection in Guatemala, the flowering spadices at anthesis attract males of a blue-green orchid bee (Apidae: Euglossinae probably Euglossa viridissima Friese) in large numbers around 1200 hours. However, in spite of the frequency of these visits and the ease with which A. dressleri is hand-pollinated I have yet to witness an open-pollinated infructescence of this species develop in my collection. Nevertheless, given the attraction to this Euglossa sp. which are known to respond to specific chemical cues emitted by plants that they pollinate (Williams & Dodson, 1972), in addition to evidence that a number of Anthurium spp. are known to be pollinated by euglossine bees elsewhere in central America (Croat, pers. comm.), it seems not unlikely that A. dressleri and A. kunayalense may have very specific euglossine pollinators in nature.
In cultivation, fruits of this Anthurium dressleri ripen relatively rapidly (152-168 d, n = 13) and a fully-pollinated infructescence on a mature plant can yield more than 200 viable seeds (pers. observ.). Fruits of both species are deep violet in the apical third to half and white or greenish white on the basal portion. Until they are fully ripe, these fruits remain embedded in the infructescence’s matrix), which is also dark greenish-purple or violet in color. When ripe, the fruits are extruded by the matrix and become immediately conspicuous due to the contrasting white color of the fruits’ basal half. Seeds are rather large for Anthurium spp. (to 8 mm), green in color when fully-formed, and often notched at one end. Line-breeding and further selection of seedlings of Anthurium dressleri for vigor may generate first flowering from seed within 42 mos (pers. observ.).
While apparently neither reports nor field observations of dispersal of Anthurium dressleri and A. kunayalense have been made, fruit color and structure, coupled with the available phenological data and a lack of evident recent recruitment in the populations that I have visited, strongly suggest a resident avian dispersal agent. It is tempting to speculate that this agent may be a one or a number of tanager species (Thraupidae). The wet tropical and premontane ecosystems of the Caribbean versant of eastern Panama and adjacent Colombia (both versants) contain diverse tanager faunas, including a number of endemics and several species known to feed on the fruits of Araceae (Ridgely, 1981; Hilty & Brown, 1986; pers. observ.). Neil Carroll (pers. comm.) observed that during his visits to the Rio Guanche population during the summer, he found the plants leaves to show dramatic predation by leaf cutter ants (presumably Atta sp.) and had all leaf lamina tissue removed to the primary veins. While A. dressleri and its hybrids do seem especially attractive to leaf-cutting ants when grown under semi-natural conditions in the Pacific lowlands of Guatemala (pers. observ.), I have seen little evidence of leaf predation on wild plants of either species that I have encountered in Panama.
Terrestrial or lithophytic; decumbent to short erect stem to ca. 70 cm long, 1-3.5 cm diam.; roots moderately few, brown, slender; cataphylls pale green, to 6 cm long, acuminate at apex, drying brown, persisting at upper nodes. LEAVES with petioles erect-spreading; blades held more or less perpendicular to petiole; petioles 4-5-ribbed, 9.8-33 cm long, 5-7 mm wide, narrowly to broadly sulcate adaxially (sometimes bluntly medially ribbed), suffused reddish or purplish violet especially on the adaxial surface sometimes purplish, the ribs at the apex and the base usually not undulated, sometimes those of the geniculum weakly undulated; blades narrowly ovate, acute to shortly acuminate at apex, deeply lobed at base, 14-45.5 cm long, 10-31.2 cm wide (averaging 32.5 x 22.9 cm), 1.1-1.6 times longer than broad, broadest near the middle, 0.8-2.2 times longer than petioles (averaging 1.5 times longer), russet or garnet red on young leaves; anterior lobe 11.3-34 cm long, the margins convex; posterior lobes 5-14 cm long, 4.1-13.7 cm wide, sometimes overlapping, often turned up along inner margins; sinus 5.5-11.5 cm deep, spathulate to closed, acute at apex; upper surface matte, dark green, velvety; lower surface matte, much paler, lacking whitish raised punctations; midrib raised above, acutely raised below; basal veins (2-)3-4( -8) pairs, free to base, raised above and below; petiolar plexus not conspicuous or prominently raised; primary lateral veins 2-4(-6) per side, departing midrib at 40-70° angle, raised above and below; interprimary veins flat, darker than surface; collective veins arising from the first basal vein, 4-9 mm from the margin. INFLORESCENCE erect, shorter than the leaves; peduncle terete or with several sharp ribs, suffused reddish or purplish violet, 9-31 cm long; spathe moderately thin, white or greenish white, occasionally with pink tinges, narrowly ovate to lanceolate, 2.7-7.5 cm long, 0.8-2.5 cm wide, broadest in the lower one-third, acuminate to caudate-acuminate at apex, obtuse to cordate at base, inserted at 35° angle on peduncle; spadix pale or bright yellow to yellowish green (B & K Yellow-green 9/2.5) or white, becoming green post-anthesis, 3.5-7.7 cm long, 6-7 mm diam. at base, 4-5 mm diam. at apex; flowers weakly 4-lobed, 2.5-3.2 mm long, 2.5-3 mm wide, the sides straight to jaggedly sigmoid, ca. 6 flowers in the principal spiral, 10 flowers in the alternate spiral; tepals glossy, weakly punctate, minutely papillate, lateral tepals 0.7-1.5 mm wide, the inner margin broadly convex; pistils green, semiglossy, weakly emergent; stigma ellipsoid, 0.4-0.5 mm long, brush-like with droplets for ca. 1 wk before stamens emerge, drying brown; lateral stamens emerging in a rapid sequence from the base, the alternate pairs emerging much later; anthers 0.4-0.5 mm long, ca. 0.8 mm wide, held above the edge of tepals, not completely emergent from beneath tepals; thecae not divaricate; pollen white. INFRUCTESCENCE pendent, to 13 cm long, 1.7 cm diam.; berries irregularly dispersed, obovoid, dark violet-purple in apical one-third, white to greenish below, 6-8 mm long, 5 mm diam., round to mammilliform at apex; seeds 2, 4-5 mm long, ca. 3 mm wide, obovoid, white (turning green in age) one end oblique, enveloped in a semi-translucent appendage.