Philodendron ligulatum var. heraclioanum Croat, var. nov.
TYPE: Panama. Darién: Parque Nacional Cerro Pirre, vicinity of station along Río Perisenico, 110 m, 8E01'N, 77E44'W, 26 July 1994, Croat & Zhu 77098 (holotype, MO-- 04619347--9; isotypes, AAU, B, CAS, CM, COL, CR, DUKE, F, GB, GH, HUA, IBE, K, L, M, MEXU, NY, OOM, P, PMA, QCA, SEL, TEX, U, US, VEN, WIS). Figures 274--276.
Internodia 1 cm longa, 1.1--2.5 cm diam.; cataphylla 15--20 cm longa, obtuse 2-costata, decidua; petiolus acute D-formatus, (8.5)20--28 cm longus, marginibus alatis; lamina (29)46--61 cm longa, (8.5)12--15 cm lata, oblongo-elliptica vel anguste oblanceolato-elliptica, obtusa basi, in sicco nigrescens; inflorescentia 1; pedunculus (5)13--15 cm longus, 1 cm diam.; spatha 10--12 cm longa.
Internodes short, to 1 cm long, 1.1--2.5 cm diam., usually longer than broad, medium green, semiglossy, drying pale yellow-brown, conspicuously and irregularly ridged and cracked; roots moderately few, to 30 cm long, 4 mm diam., reddish brown, weakly glossy, finely scaly; cataphylls 15--20 cm long, bluntly 1--2-ribbed, sharply 2-ribbed near apex; petioles (8.5)20--28 cm long, sharply D-shaped, with adaxial margins winged (to 6 mm high); blades oblong-elliptic to narrowly oblanceolate-elliptic, obtuse to narrowly rounded at base, (29)46--61 cm long, (8.5)12--15 cm wide ((2.9)4.3--5.4 times longer than wide), (2--2.6(6.3) times longer than petiole), upper drying blackish, lower surface matte, heavily tinged or mottled violet-purple or maroon, drying dark brownish black; midrib narrowly rounded and paler than surface below with maroon spots on older veins; basal veins lacking; primary lateral veins 5--12 per side, departing midrib at a 40--50E angle, to the margins, green with maroon spots on older plants. INFLORESCENCES 1 per axil; peduncle (5)13--15 cm long, 1 cm diam.; spathe pale green, 10--12 cm long, to 6.5 cm wide when flattened, tinged violet-purple on outer margin and at base outside and at base inside; spathe blade greenish inside; spathe tube pale green, glossy inside; spadix 9.5--12 cm long; pistillate portion 4.3 cm long in front, 3.6 cm long in back; ovules 2 per locule, contained within transparent matrix, style similar to style type C; style funnel shallow to moderately deep.
INFRUCTESCENCE with berries oblong-elliptic, 3 mm long; seeds oblong, light yellow-brown, 1.4 mm long, 0.4 mm diam., narrowly ribbed longitudinally. JUVENILE blades with lower surface heavily tinged maroon.
Flowering in Philodendron ligulatum var. heraclioanum is poorly known. Pre-anthesis flowering collections were seen from March and in July. The inflorescence on the July collection was nearly fully emerged so that it would certainly have opened in less than one month. Immature fruits were seen in October.
Philodendron ligulatum var. heraclioanum is endemic to Panama, known definitely only from the type locality at the base of Cerro Pirre in Darién Province from 50 to 200 m elevation in a Premontane wet forest life zone.
This variety is characterized by its bluntly two-ribbed cataphylls, sharply D-shaped, marginally-winged petioles, and the oblong-elliptic to narrowly oblanceolate-elliptic, blackish drying blades heavily tinged with maroon on the lower surface when young.
Philodendron ligulatum var. heraclioanum differs from both P. ligulatum var. ligulatum and P. ligulatum var. ovatum in its sharply D-shaped petioles with undulate-winged margins, in having 2 ovules per locule without an obvious ovule sac (versus one ovule per locule contained in an ovule sac for the other two varieties), and in the maroon coloration of the lower surface of the young blades. In contrast, the other two varieties have petioles which are typically terete or subterete, merely obtusely flattened adaxially.
Philodendron ligulatum var. heraclioanum may be confused with P. pseudauriculatum, but the latter differs in having the petioles unwinged and, at most, obtusely flattened adaxially. In addition, P. pseudauriculatum has never been reported to have the blades purplish on the lower surfaces.
A collection from San Blas in far eastern Panama is probably also this species, it differs in having much longer internodes (to 10 cm long and drying ca. 5 mm diam.) and proportionately shorter petioles.
Philodendron ligulatum var. heraclioanum is named in honor of Panamanian collector Heraclio Herrera, who was one of the first to collect the taxon.
Additional specimens examined.
PANAMA. Darién: Cerro Pirre National Park, W side of Cerro Pirre, base camp, 50 m, 8EN, 77E48'W, Croat 68963 (MO); Parque Nacional Darién, Estación Rancho Frío, N base of Cerro Pirre, ca. 9 km S of El Real, Quebrada Perisenico, 70--270 m, 8E01'N, 77E44'W, Hammel et al. 16145 (MO). San Blas: Quebrada Masargandí, Isla de Tubuala, 200--400 m, 8E54'N, 77E46'W, Herrera 1304 (CAS, CM, MO, PMA).