Philodendron hammelii Croat, sp. nov.
TYPE: Panama. Coclé: Alto Calvario, ca. 6 km N of El Copé, Pacific drainage, on ridge W of sawmill, 850--1100 m, 89E39'N, 80E36'W, Hammel 3551 (holotype, MO--2658909). Figure 217.
Planta terrestris; internodia 1--1.5 cm longa, 8--12 mm diam.; cataphylla 11.5 cm longa, 1-costata, persistentia ut reticulum tenue fibrarum; petiolus subteres, 31--32 cm longus, 2--3 mm diam., dense obtecta squamis latis, pallidis prope apicem; lamina ovato-cordata, 21--22 cm longa, 13--16 cm lata, in sicco canoviridis supra, flavibrunnea infra; inflorescentia 1; pedunculus 4.5 cm longus, 4 mm diam.; spatha 11 cm longa; pistilla 6-locularia; loculi 14-ovulati.
Terrestrial; internodes 1--1.5 cm long, 8--12 mm diam., drying yellow-brown, semiglossy, conspicuously ridged; roots drying reddish brown to brown, slender, numerous per node; cataphylls to 11.5 cm long, 1-ribbed, drying yellowish brown, thin, smooth (not scaly), persisting as a thin, pale reticulum of branched tan fibers; petioles 31--32 cm long, 2--3 mm diam., subterete, drying weakly glossy, smooth or at most, weakly granular, surface densely covered with broad pale scales near apex, the scales closed and overlapping, mostly less than three times longer than broad; blades ovate-cordate, subcoriaceous, shortly acuminate at apex, cordate at base, 21--22 cm long, 13--16 cm wide (1.4--1.5 times longer than wide), (0.66--0.67 as long as petiole), upper surface dark green, subvelvety and glistening, drying grayish green, lower surface much paler, semiglossy, drying yellowish brown and moderately glossy; anterior lobe 15--16.7 cm long, 15.3 cm wide (2.2--2.6 times longer than posterior lobes); posterior lobes 6.5--6.7 cm long, 7 cm wide, rounded; sinus obovate to narrow hippocrepiform and closed; midrib drying sunken and concolorous above, convex, matte below; basal veins 6 per side, with 2 free to base, third and higher order veins coalesced 1 cm, sunken above, convex below; posterior rib not naked; primary lateral veins 3 per side, departing midrib at a 40--45E angle, quilted-sunken above, round-raised or raised, darker below; minor veins distinct, arising from both the midrib and primary lateral veins; "cross-veins" prominently raised upon drying.
INFLORESCENCES probably 1 per axil; peduncle 4.5 cm long, 4 mm diam., more or less terete, glabrous; spathe 11 cm long, (2.4 times longer than peduncle), green, drying dark reddish brown; spadix sessile; 9.5--10.5 cm long; pistillate portion 3 cm long, 1 cm diam.; staminate portion 6.5--7.5 cm long, 1--1.5 cm diam.; pistils 1.5 mm long, 1.9 mm diam.; ovary 6-locular, 1.2 mm diam., locules 1 mm long, 0.3 mm diam., ovule sac 0.1--0.2 mm long, with axile placentation; ovules ca. 14 per locule, 2-seriate, contained within small, cloudy, gelatinous ovule sac, 0.1--0.2 mm long, longer than funicle; funicle to 0.1 mm long, adnate to lower part of partition, style similar to style type B; style apex flat; stigma hemispheroid, lobed, 1 mm diam., 0.3--0.4 mm high, covering entire style apex, depressed shallowly at center; the androecium truncate, more or less prismatic, margins irregularly 4--5-sided, ca. 1 mm long; sterile staminate flowers irregularly 4--5-sided, 1.6--2.1 mm long.
Flowering in Philodendron hammelii apparently occurs in the early wet season, based on a single collection made in June.
Philodendron hammelii is endemic to Panama, known only from the type in Coclé Province in Premontane rain forest at 850 to 1100 m elevation.
Philodendron hammelii is a member of P. sect. Philodendron subsect. Achyropodium. This species is characterized by its short, slender internodes, persistent, thin, pale network of branched cataphyll fibers, petioles longer than the blades and densely covered with broad, pale scales near the apex, and ovate-cordate, yellow-green-drying blades.
Philodendron hammelii is superficially most similar to P. colombianum R. E. Schult. from the Amazon basin. These species have similarly shaped blades drying yellow-green with prominent "cross-veins" and persistent, pale cataphyll fibers. Philodendron colombianum differs, however, in having the blade sinus acute at apex and petioles lacking scales.
In Panama, this species might be confused with P. squamipetiolatum, which also has scaly petioles. It differs in having blades with a more arcuate sinus and petioles conspicuously long-scaly throughout most of their length.
The species is named in honor of Barry Hammel of the Missouri Botanical Garden who has collected many important Araceae in Panama and Costa Rica, including the type specimen.
