Usually epiphytic or hemiepipliytic; stem appressed-climbing, grayish green, sap strongly thyme-scented; internodes short, thick, semiglossy, 4÷7.5 cm diam., broader than long, pale green to gray, epidermis thin, yellow, fragmented, without fissures; roots moderately lew per node, drying dark brown to ca. 5 mm diam., epidermis semiglossy, flaking; eataphylls 16-46 cm long, sharply 2-ribhed (ribs to 1.5 cm high), usually tinged red, drying brownish yellow, often glossy (as if surface is shellacked), broadly concave to broadly D-shaped adaxially, persisting semi-intact, finally as a dense mass of whitish libers; margins acute; petioles 35÷83 cm long, 1÷2.2 cm diam., subterete to D-shaped, firm to moderately spongy, medium green, drying yellowish brown, obtusely flattened with obtuse medial rib toward apex adaxially, surface semiglossy and obtusely striate; blades ovate, suhcoriaceous, semiglossy, moderately bicolorous, acuminate to abruptly acuminate at apex (the acumen strongly inrolled, 2÷8 mm long), cordate to sagittate at base, 30-77 cm long, (17.5)23-64 cm wide (1-1.7(2.7) times longer than wide), (0.6-1.2 times longer than petiole); upper surface dark green, semiglossy to subvelvety-matte; lower surface semiglossy or rarely matte, moderately paler; anterior lobe 23÷57 cm long, 24.5÷64 cm wide (1.6÷2.7 limes longer than posterior lobes); posterior lobes 8.5-28 cm long, 10-29.6 cm wide, obtuse to broadly obtuse; sinus usually spathulate, 8-20 cm deep; midrib flat to broadly convex, paler than surface above, convex to narrowly rounded, concolorous or slightly darker than surface below; basal veins (1)6÷7(8÷9) per side, with 0÷1(2) free to base, most of the remainder coalesced 1÷5.5 cm, 2 coalesced lo 11 cm; posterior rib usually naked, 1÷3 cm long; primary lateral veins 3÷8 per side, departing midrib at a usually 40÷70¡ angle, quilt-ed-sunken to sunken, paler than surface above, convex and slightly paler than surface below; tertiary veins visible and darker than surface below; nminor veins conspicuous, arising from both the midrib and primary lateral veins, moderately prom-inulous on drying, alternating with secretory ducts perpendicular or more frequently oblique, sometimes branching; "cross-veins" weakly parted.

INFLORESCENCES erect to erect-spreading, (1)2-3 per axil; peduncle 2-9 cm long, 8÷14 cm diam., pinkish red. white striate, especially toward apex; spathe 10-17 cm long (1.9-7 times longer than peduncle), weakly constricted, oblong-ellipsoid; spathe blade light green outside, cream, pale li-neate in upper one-half inside; spathe tube green, tinged red outside, 6-9 cm long, red with conspicuous resin canals inside; spadix tapered to somewhat ovate, weakly protruding, 8.8÷14.4 cm long; pistillate portion weakly ovoid, whitish, (2)3^1,.9 cm long, 2-2.4 cm diam. throughout, 1.4-1.5 cm diam. at apex, 1.4÷1.9 cm diam. at middle, 1.4÷ 1.8 cm wide at base; staminate portion 5.7÷10.8 cm long; fertile staminate portion bluntly tapered at apex, 1.1÷1.4 cm diam. at base, 1.2÷2.3 cm diam. at middle, 1(1.7) cm diam. ca. 1 cm from apex, broadest at upper two-thirds, broader than the pistillate portion, slightly narrower than the sterile portion; sterile staminate portion broader than the pistillate portion, 1.4.÷2.5 cm diam.; pistils (1)3÷ 3.9 mm long, 1.5÷1.9(3.8) mm diam., margins broadly rounded and slightly raised above the apex; ovary 4-6-locular, 1.9-2.5 mm long, 1.3-1.9(3.8) mm diam., with axilc placentation; locules 1.9-2.5 mm long, 0.4÷0.7 mm diam.; ovule sac not present or to 1.9 mm long; ovules 10-14(18) per locule, 2-seriate, rarely contained within translucent or transparent envelope, 0.1÷0.3 mm long, longer than funicle; funicle 0.1-0.3 mm long, adnate to lower part of partition, style 0.8÷1.2 mm long, 1.5÷ 1.9(3.6) mm diam., similar to style type B; style apex barely raised, button-like, broadly concave, medial apex with a whitened margin, raised and apparently like type D on drying; stigma subdis-coid, truncate, 1.4÷1.6 mm diam., 0.3÷0.4 mm high, covering ± entire style apex, sometimes depressed shallowly and medially; the androecium truncate, oblong, prismatic, margins irregularly 4÷ 5-sided, sometimes scalloped, 1 mm long, 1.8÷2.1 mm diam. at apex; thecae ± oblong, 0.4-0.5 mm wide, ± parallel to one another; sterile, staminale flowers blunt, irregularly 4--6-sided, prismatic, 2.5÷ 3.5 mm long, (1.4)1.8-2.2 mm wide.

INFRUCTESCENCE with pistillate spadix 5÷6 cm long, 3.5 cm diam.; berries white, 1.1 cm long, 4-^1..6 mm diam.; seeds 1.4 mm long, 0.5 mm diam., cream-colored.

Flowering specimens of Philodendron schottianum, have been collected only from March and June, but post-anthesis collections have been made from March through August. Immature fruiting collections have been collected from January, May, September, and November. The immature January fruiting collection is a clear indication that the species must flower much earlier in the dry season than March (as indicated above). Perhaps it flowers throughout the dry season. In the cloud forest regions where this species occurs the dry season would not be very severe.

Philodendron schottianum. ranges from Costa Rica to Panama at (490)730 to 2250 m in Premontane rain forest and Tropical Lower Montane wet forest life zones. In Panama, this species ranges no further east than Veraguas (Cerro Tute), except for a disjunct occurrence on Cerro Jefe in Panama Province. All Costa Rican collections are from the northern slopes of the Cordillera Central in Alajue-la, Heredia, and San Jose, and the northern end of the Cordillera de Talamanca in the Tapanti region of Cartago Province. It is to be expected throughout much of the Cordillera de Talamanca.

Philodendron schottianum is a member of P. sect. Philodendron subsect. Philodendron sex. Fibrosa. This species is distinguished by its short, thick in-temodes; sharply 2-ribbed cataphylls persisting as a dense mass of fibers (frequently with patches of glossy, yellowish to orange-brown epidermis); obtusely to sharply D-shaped petioles drying somewhat grayish or rarely yellowish and glossy; large, broadly ovate blades with a deep, usually spathulate sinus, usually pale-drying primary lateral veins; and rather conspicuous secretory canals between the veins; 2-3 short-pedunculate inflorescences per axil; and scarcely constricted, externally green spathes red on the tube within.

In Costa Rica and at higher elevations in Panama, such as on Cerro Colorado and on Cerro Pate de Macho (1000 to 2200 m), the petioles are sub-terete or obtusely flattened adaxially. At lower elevations in Bocas del Toro, Veraguas, and Code, the petioles become D-shaped to sharply D-shaped with erect margins, and at the lowest elevations they are nearly always wing-margined.

In Bocas del Toro Province, Panama, at middle elevations and in mesic situations, this species is most easily confused with P. findens, which also has sharply D-shaped petioles. Philodendron findens also has spathes which, like those of P. schotlianum, are barely constricted midway. In rare situations where the blades of P. findens do not promptly tear into narrow segments, P. findens can be distinguished from P. schottianum by having primary lateral veins of the lower surface drying darker than the surface.

In central Panama, P. schottianum can also be confused with P. ilanense. Both P. schottianum and P. Ilanoense occur in the Cerro Jefe region, though P. schottianum has been collected there only once, northeast of Altos de Pacora. This collection (Croat 68691) exhibits most of the diagnostic fealures u( P. schottianum, especially the persistent yellowish, semi-intact cataphylls, and the acutely D-shaped petioles with an obtuse medial rib (unknown in P. Ilanense), but has a blade shape midway between that of P. schottianum and P. Ilanense (blade length/ width ratio 1.5 vs. an average of 1.4 for P. Ilanense and 1.65 for P. schottianum). Philodendron Ilanense differs in having at most obtusely flattened petioles and in lacking the conspicuous yellowish cataphylls of P. schottianum. Philodendron Ilanense also rarely occurs above 500 m (to 950 m), whereas P. schottianum only rarely occurs to as low as 500 in.

Philodendron schottianum can be confused witli P. thalassicum and P. alticola, especially in Costa Rica. Philodendron thalassicum differs in having bluish green leaf blades that are glaucous beneath and sharply D-shaped petioles drying somewhat blackened rather than merely obtusely flattened and light yellow-brown, as in P. schottianum. Philodendron alticola differs in usually having narrower leal blades (usually more than 1.8 times longer than wide) and stigma tubes exserted as minute funnels on the dried stigma.

Philodendron dodsonii may also be confused with P. schottianum. The former differs in occurring usually at lower elevations principally in tropical wet forest and premontane wet forest, and in having larger leaf blades, more long-pedunculate inflorescences, and longer spathes with a normal constriction above the spathe tube.

One collection, Grayum 7333, differs from more typical collections in having blades reportedly matte on both surfaces and lacking prominulous minor veins and conspicuous secretory ducts (so evident in other material of this species where they alternate with the minor veins). In addition, this specimen has darker-drying petioles and more fragmentary old cataphylls as well as intact cataphylls (perhaps juvenile?) drying brown (rather than the typical brownish yellow) and a spathe with a narrowly acuminate portion extending a lull 5 cm beyond the end of the spadix. On other specimens, the spadix ends only about 1 cm or less short of the end of the spathe.

Hammel et al. 14705 is unusual in lacking cataphylls, suggesting that they might have been deciduous (or forcibly removed during preparation).