ContentsPhilodendron grayumiiPhilodendron mexicanum

Philodendron knappiae Croat, sp. nov.

TYPE: Panama. Chiriquí: Cerro Hornito, in elfin forest on ridges and summit, approached from Los Planes de Hornito, 2100 m, 8E42'N, 82E06'W, 14 Mar. 1982, Knapp, Kress & Hammel 4219 (holotype, MO--3043611). Figures 240, 244, 249, 254.

Planta terrestris aut hemiepiphytica; internodia 0.5--7 cm longa, 1--1.7 cm diam., in sicco brunnea; cataphylla 10--18 cm longa, acute 2-costata, sulcata adaxialiter, viridia, decidua; petiolus obtuse D-formatus, 14--19 cm longus, in sicco 2--7 mm diam.; lamina ovato-triangularis, cordata basi, 16--23.5 cm longa, 7.5--11.5 cm lata; inflorescentia 1; pedunculus 2--3 cm longus, 5--6 mm diam.; spatha 7--8 cm longa, extus viridis, intus subrosea; pistilla 4-locularia; loculi 4-ovulati.

Terrestrial or hemiepiphytic; stems usually erect; internodes short, somewhat flattened on one side with marginal ribs, moderately glossy, 0.5--7 cm long, 1--1.7 cm diam., longer than broad below, short near apex, medium green, epidermis smooth, light brown; cataphylls 10--18 cm long, sharply 2-ribbed, green, sulcate adaxially, margins weakly raised abaxially, deciduous; petioles 14--19 cm long, 2--7 mm diam., bluntly D-shaped, green, tinged reddish; blades ovate-triangular, subcoriaceous, bicolorous, long-apiculate at apex, cordate at base, 16--23.5 cm long, 7.5--11.5 cm wide (1.8--3 times longer than wide), (1.1--1.4 times longer than petiole), about equal in length to petiole, upper surface semiglossy, drying dark brown, lower surface slightly paler, drying dark yellow-brown or dark yellow-green; anterior lobe 12--18.5 cm long, 10.6--13 cm wide (2.2--3.3 times longer than posterior lobes); posterior lobes 5--8 cm long, 5--6.5 cm wide (1.4--1.8 times longer than wide), narrowly to obtusely rounded; sinus hippocrepiform, 3--5.5 cm deep; midrib broadly convex, paler than surface above, convex, reddish or paler than surface below; basal veins 3(5) per side, with 0--1 free to base, 2--3 coalesced 1--1.5 cm; posterior rib naked; primary lateral veins 5--7 per side, departing midrib at a (40)55--70 (lowermost to 80E) angle, arcuate-ascending to the margins, weakly visible above, weakly raised, often reddish below; minor veins distinct below, arising from the midrib only; secretory ducts present but inconspicuous.

INFLORESCENCES 1 per axil; peduncle 2--3 cm long, 5--6 mm diam.; spathe 7-8 cm long, (2.3--3.6 times longer than peduncle), weakly constricted above the tube, 1.5 cm diam. at constriction, green throughout, pinkish within; spathe tube 3--4 cm long, 1.9 cm diam.; spadix 5.5--7 cm long, white throughout; pistillate portion 1.2 cm long, 1 cm diam.; staminate portion 4.3--5.8 cm long, 8--12 mm diam.; pistils 1--1.3 mm long, 0.7 mm diam.; ovary 4-locular; locules 0.8 mm long, 0.3-0.4 mm diam., with axile placentation; ovules 4 per locule, 2-seriate, 0.2 mm long, longer than funicle; funicle 0.1 mm long, adnate to lower part of partition, style similar to style type B; style apex flat to concave; stigma more or less hemispheroid, unlobed, 0.8 mm diam., 0.2 mm high, covering entire style apex; the androecium truncate, more or less prismatic, margins irregularly 4--6-sided, mostly 4--5-sided, 0.8--1.1 mm long; thecae oblong, 0.4 mm wide, more or less parallel to one another, not contiguous; sterile staminate flowers irregularly 4--6-sided, 0.9--1.1 mm long.

Flowering in Philodendron knappiae apparently occurs in the dry season and is documented by only two fertile collections, one flowering and one post-anthesis, both made in March.


Philodendron knappiae is endemic to western Panama, known only from the type locality in Chiriquí Province on Cerro Hornito in Tropical Lower Montane rain forest at 2100 m elevation.

Philodendron knappiae is a member of P. sect. Calostigma subsect. Macrobelium ser. Macrobelium. This species is recognized by its relatively small stature, short internodes (distally) with smooth, brown epidermis, adaxially sulcate, sharply two-ribbed, green but densely short-red-lineate, deciduous cataphylls, bluntly D-shaped petioles (about as long as the blades), small, ovate-triangular dark brown-drying blades with a hippocrepiform sinus, and solitary inflorescences with the spathe green outside and pink inside.

The species is perhaps most easily confused with P. wilburii, which has leaf blades of similar size and shape. The latter species differs in having longer internodes drying with a tan, glossy epidermis, thicker blades drying yellowish green to dark olive brown above, 2--3 inflorescences per axil, and 2 ovules per locule (versus 4 per locule for P. knappiae).

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Additional specimens examined.

PANAMA. Chiriquí: Cerro Hornito, above Los Planes de Hornito, 1750 m, 8E41'N, 82E10'W,Croat 67982 (CM, MO); 2100 m, Kress et al. 82-1363 (DUKE).