ContentsPhilodendron jodavisianumPhilodendron illanoense

Philodendron lazorii Croat, sp. nov.

TYPE: Panama. Canal Area: vic. Madden Lake, along both sides of stream SSE of pumping station (SE of dam), 140 m, 9E13'N, 79E37'W, 18 Jan. 1990, Croat 69833 (holotype, MO--3789003--5; isotypes, AAU, B, CAS, CM, COL, CR, F, GH, K, MEXU, NY, PMA, QCNE, RSA, SCZ, TEX, US, VEN). Figures 13--14, 250--252, 255--258.

Planta hemiepiphytica; internodia 1--4 cm longa, 5 cm diam.; cataphylla acute D-formata, persistentia semi-intacta nodis superioribus, demum decidua; petiolus teres, 37--63(76) cm longus, 5--6 mm diam.; lamina late ovata, 32-54 cm longa, (22)34--49 cm lata, cordata basi, in sicco canoviridis; sinus hippocrepiformus vel obovata; inflorescentia 2; pedunculus 8.6--17 cm longus; spatha 12--13.5 cm longa; pistilla 5--6-locularia; loculi 10--14-ovulati.

Hemiepiphytic; stem appressed-climbing (scandent as juvenile); internodes weakly striate, 1--4 cm long, 5 cm diam., more or less broader than long, light olive-green to dark yellow-green, glossy, roots 1--3 per node, dark brown to reddish brown, matte, smooth to densely scaly, to 30 cm or longer, 3--5 mm diam., feeder roots to 8 mm diam., densely scaly; cataphylls 17--19 cm long, pale yellow-green, sharply D-shaped, margins acutely raised, persisting semi-intact at upper nodes with a dense reticulum of coarse fibers, often overlain with a thin, fragmented epidermis, becoming dilacerated, eventually deciduous; petioles 37--63(76) cm long, 5--6 mm diam., terete, dark green, firm, flexible, surface matte, faintly dark green striate; blades broadly ovate, subcoriaceous, long-acuminate at apex, cordate at base, 32--54 cm long, (22)34--49 cm wide (0.97--1.4 times longer than wide, averaging 1.13 times), (0.65--0.9 times the petiole length), slightly shorter in length than petiole, upper surface dark green, drying gray-green, weakly to semiglossy, lower surface drying gray-green, matte, much paler; anterior lobe 27--33 cm long, 36 cm wide (1.6--2.2 times longer than posterior lobes); posterior lobes 13--17 cm long, 16--19.5 cm wide, obtuse; sinus hippocrepiform to obovate, 9.5--11.5 cm deep; midrib flat to broadly raised, concolorous to slightly paler than surface above, narrow-rounded to bluntly acute, darker than surface below; basal veins (5)6--7 per side, with 0--1 free to base, 3rd and higher order veins coalesced 2--4.5 cm, obscure; posterior rib 2--3 cm long along the sinus; primary lateral veins 3--4 per side, departing midrib at a 40--50 then to 70E angle, straight to weakly arcuate to the margins, weakly and obtusely sunken and concolorous or paler above, convex and darker than surface below; minor veins moderately distinct, arising from both the midrib and primary lateral veins, drying weakly puckered and darker than surface below, upper surface usually drying with whitish cells visible, lower surface drying smooth and minutely brownish to whitish speckled. INFLORESCENCES 2 per axil; peduncle 8.6--17 cm long, to 1.1 cm diam., medium green, lightly white-striate, heavily white-striate nearest apex; spathe 12--13.5 cm long, (spathe equal in length to or slightly shorter than peduncle), constricted above the tube, 2.9 cm diam. at constriction, margins pale to creamy; spathe blade yellowish green outside, 8 cm long, (opening 4 cm wide), creamy on outer margins, glossy inside; spathe tube medium green, finely white-striate with pale margins outside, 5 cm long, 3.3 cm diam., pale yellowish green, glossy inside; spadix bluntly pointed at apex, 10.9--11.3 cm long, constricted 1.5 cm above base of fertile staminate portion; pistillate portion pale yellowish green, 3.3--4 cm long, 1 cm diam. at base, 1.5 cm diam. midway, 1.4 cm diam. at apex; staminate portion 7.8--9.3 cm long; fertile staminate portion creamy white, 1.7 cm diam. at middle, 11 mm diam. ca. 1 cm from apex; sterile staminate portion barely detectable, creamy white, drying darker than fertile staminate flowers, 1.7 cm diam.; pistils 1.9--2.5 mm long; ovary (4)5--6-locular, 1.1 mm diam., locules 1.1--1.6 mm long, 0.3--0.4 mm diam., with axile placentation; ovules 10--14(18) per locule, 2-seriate, 0.3 mm long, longer than funicle; funicle 0.1--0.2 mm long, adnate to lower part of partition, style 0.9 mm diam., similar to style type D; style apex more or less rounded to bluntly pointed; style boss broad and pronounced; stigma subdiscoid, unlobed, more or less truncate, 1.5 mm diam., 0.3 mm high, covering entire style apex, depressed shallowly and medially; the androecium truncate, prismatic, oblong, margins irregularly 4--6-sided, 0.7--1 mm long; thecae oblong, 0.4--0.5 mm wide, not contiguous, more or less parallel to one another; sterile staminate flowers irregularly 4--6-sided, slightly clavate to prismatic, 1.2--1.9 mm long. JUVENILE plants with internodes matte, gray-green, 6 cm long, 7 mm diam.; petioles terete; blades weakly velvety; upper surface more or less glistening-glossy, lower surface matte, much paler, with flecks of brilliance; minor veins very distinct, darker than surface.

Flowering in Philodendron lazorii occurs in the late dry season and early rainy season (March through June), with mature fruits in August. Immature fruits have been collected in March and June, which indicates that there must be flowers in the late wet season as well (or perhaps it indicates bimodal flowering).

Philodendron lazorii is endemic to Panama, known from the type locality, a region of limestone outcrops near Madden Lake, at about 100 m elevation in Tropical moist forest, and in Darién Province at 250 to 1050 m in Tropical moist forest and Premontane wet forest.

Philodendron lazorii is a member of P. sect. Philodendron subsect. Philodendron ser. Fibrosa. This species is distinguished by its thick, short internodes, cataphylls persisting semi-intact with an organized network of yellow-brown fibers, terete petioles averaging 1.25 times longer than the blade, and broadly ovate, gray-green-drying blades matte on the lower surface.

Philodendron lazorii is probably most closely related to P. panamense, which has similar inflorescences. The latter species differs in having semiglossy, ovatetriangular blades usually 1.3 or more times longer than wide (averaging 1.5 times longer than wide) and petioles commonly shorter than the blade. In addition, it has generally shorter peduncles (usually shorter than the spathe).

This species is also similar to P. jefense. See that species for a discussion of the differences.

Philodendron lazorii is named in honor of one of its original collectors, Robert Lazor (Army Corps. of Engineers, Vicksburg), who collected in Panama while a student at Florida State University.

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Additional specimens examined.

PANAMA. Canal Area: Madden Lake Cave area, ca. 9E13'N, 79E37'W, Tyson & Lazor 6266 (FSU, IBE); Salvador Hill, near Juan Mina, Bartlett & Lasser 16785 (MICH, MO). Darién: along trail from base camp to Rancho Frío on slopes of Cerro Pirre, 200--450 m, 7E58'N, 77E43'W, Croat & Zhu 77126 (CAS, CM, CR, MO); W side of Cerro Pirre, 800--1050 m, 7E56'N, 77E45'W, Croat 68953 (DUKE, HUA, M, MO).