ContentsPhilodendron smithiiPhilodendron sulcicaule

Philodendron straminicaule Croat, sp. nov.

TYPE: Panama. Chiriqui: Fortuna Dam area, trail to meteorological station of Rio Homito, ca. 0.5 km S of Centro de Cientificos, 845'N, 8218'W, 23 June 1994, Croat & Zhu 76302 (holotype, MO-4610957-9; isotypes, AAU, B, CAS, COL, CR, F, GH, K, M, MEXU, NY, PMA, QCNE, S, SEL, US, VEN). Figures 6, 376, 389-392.

Planta hemiepiphytica; internodia 1.55(12) cm longa, 23.5 cm diam., plus minusve fragilia, canoviridia vel atriviridia, in sicco straminea; cataphylla (17)20-35 cm longa, decidua; petiolus subteres, (27)32-59 cm longus, 5-12(17) cm diam.; lamina triangulari-ovato-cordata, (27)33-55 cm longa, (11)19.7-31 cm lata, cordata basi; inflorescentia 2-3(5); pedunculus (4.5)5.6-18 cm longus; spatha 7-18.5 cm longa; lamina spathae alba in superficiebus ambabus; tubo spathae exius pallide viridi, intus rubroviolaceo vel marronino; pistilla 46(10)-locularia; loculi 1-ovulati; baccae virella-albae vel lavandulae.

Hemiepiphytic; stem appressed-climbing, leaf scars conspicuous, 11.6 cm long, 1.21.7 cm wide; internodes glossy to semiglossy, brittle, somewhat scurfy, 1-5(12) cm long, 2-3.5 mm diam., longer than broad, dark green, soon gray- green, finally light tan, drying straw-colored, sometimes with a narrow ring of yellow-brown periderm at the nodes; epidermis transversely fissured in part, sometimes deeply fissured and cracking free on drying; roots blunt, to 30 cm or longer, 4 mm diam., yellow-green, weakly glossy (fresh), drying reddish brown with minute scales in age; cataphylls somewhat spongy, to (17)20-35 cm long, variously ribbed, sometimes D-shaped or unribbed, more frequently bluntly to sharply 1- or 2-ribbed (sometimes unribbed in Code), emarginate at apex, pale green to pale yellowish to whitish, margins clear, sometimes closely dark green short-lineate, sometimes moderately red-purple-spotted (more so at base) throughout, ribs darker, drying greenish or brownish, deciduous, persisting intact; petioles (27)32-59 cm long, 5-12(17) mm diam., subterete, spongy, medium green, obtusely flattened adaxially, rounded adaxially, surface semiglossy, faintly dark lineate; blades triangular-ovate-cordate, subcoriaceous, semiglossy, bicolorous, long acuminate at apex, cordate at base, (27)3355 cm long, (11)19.7-31 cm wide (1.3-2.3 times longer than wide), (0.71.5 times longer than petiole), margins hyaline, lower surface drying green to yellow-green, densely glaucous with secretory ducts visible; anterior lobe (18.7)27-38.6(47) cm long, 17.6-27.6 cm wide (2.4-4.5 times longer than posterior lobes), margins straight to moderately concave; posterior lobes directed toward base, rarely reflexed-spreading, sometimes overlapping when posterior lobes are held somewhat upward al an angle to the midrib, (7)8.515.5 cm long, 7.513 cm wide, obtuse to rounded; sinus hippocrepiform, rarely closed, 2.6-14 cm deep; midrib flat to broadly rounded, paler than surface above, convex to narrowly rounded, paler than surface below; basal veins 46(7) per side, with 01 free to base, the remainder coalesced 1.25 cm, 2 coalesced 3.57 cm; posterior rib naked 0.51.5 cm; primary lateral veins 3-6 per side, departing midrib at a 45-65 angle, acutely ascending then weakly arcuate to straight to the margins, obscure, sunken and concolorous above, convex, darker than surface or paler than surface below; interprimary veins raised and darker than surface below; minor veins moderately distinct, fine, darker than surface, arising from both the midrib and primary lateral veins, drying minutely granular, prominulous and alternating with secretory ducts.

INFLORESCENCES erect, usually 23 (sometimes to 5) per axil; peduncle (4.5)5.618 cm long, terete, pale to medium green, faintly short-lineate to densely speckled; spathe 7 18.5 cm long (0.91.8 times longer than peduncle), moderately constricted above the tube; spathe blade pale green to white on both surfaces, acuminate at apex; spathe tube dark green, finely pale lineate, glossy outside, 48.5 cm long, 1.53 cm diam., reddish violet to maroon or magenta inside; spadix sessile; erect at anthesis, 7.613 cm long; pistillate portion 2.2-3.7(6.5) cm long, 1-1.4(2) cm diam. at middle, tapered slightly toward both ends; staminate portion clavate, 5.27.7 cm long; fertile staminate portion white, 810 mm diam. at base, 1-1.5 cm diam. at middle, 4-8 mm diam. ca. 1 cm from apex, broadest at the middle, abruptly tapered toward apex, weakly constricted just above the sterile portion; sterile staminate portion usually broader than the pistillate portion at anthesis, 8-15 mm diam., the lowermost flowers sometimes drying whitened; pistils 1.1-1.7(3.4) mm long, 7-9(17) mm diam.; ovary 4-6(10)-locular, 0.5-0.7(2.2) mm long, 0.7-0.9(1.7) mm diam., with sub-basal placentation; locules 0.50.7(2.1) mm long, 0.2 0.3(0.6) mm diam.; ovule sac 0.5-0.7 mm long; ovules 1 per locule, contained within sticky, transparent, gelatinous ovule sac, 0.20.3 mm long, as long as funicle; funicle 0.2-0.3 mm long (can be pulled free to base), style 0.5-0.8(1) mm long, 0.6-0.7(1.7) mm diam., drying doughnut-shaped, similar to style type C; style funnel shallow with a small ring of stylar canals near the base; stigma subdiscoid, truncate, 0.4-0.5(0.8) mm diam., 0.1-0.3 mm high, covering almost entire style apex, with 15 depressions when dried, papillate, sessile, matte;

the androecium truncate, prismatic, margins 4 5-sided, 0.61 mm long, 1.11.3 mm diam. al apex;

thecae oblong, 0.40.5 mm wide, parallel to one another and nearly contiguous to contiguous; pollen spheroidal, <0.1 mm long, <0.1 mm diam., scarce; sterile staminate flowers irregularly 46-sided, blunt, prismatic, 11.3 mm long, 0.91.2 mm wide. INFRUCTESCENCE with berries pale green (immature), greenish white to lavender.

Flowering in Philodendron straminicaule is believed to occur throughout much of the dry season to the mid-rainy season (January through August) in Panama, but flowering specimens have been seen from only April through August. Post-anthesis inflorescences have been seen from as early as March, and immature fruits as early as February, making it obvious that the plants have to be in flower as early as January. Post-anthesis inflorescences have also been collected from May through September and November, and immature fruits occur in March and July. The post-anthesis inflorescences from November suggest that flowering occurs as late as September or October.

Philodendron straminicaule is known only from the Cordillera de Guanacaste in northwest Costa Rica and in western Panama, from Chiriqui and Bocas del Toro to Code Province, at (710)950 to 2200 m elevation, generally in Tropical Lower Montane rain forest and Premontane rain forest, rarely in Tropical wet forest.

Philodendron straminicaule is a member of P. sect. Calostigma subsect. Glossophyllum ser. Ovata. This species is characterized by its grayish (drying straw-colored), more or less brittle, glossy inter-nodes, which are longer than broad; deciduous cataphylls; obtusely flattened, more or less spongy petioles; and triangular-ovate-cordate, green-drying blades with the lower surface drying densely and minutely granular and secretory ducts usually prominently visible and alternating with the minor veins. Also characteristic is the white spathe blade and tube green outside and reddish violet to maroon inside.

Philodendron straminicaule is similar to P. wilburii var. longipedunculatum, but the latter species differs in having longer, more slender internodes; longer, unribbed to bluntly 1-ribbed cataphylls; typically smaller blades that dry brownish with mostly 3-4 primary lateral veins; and especially by having the peduncle usually as long as or even longer than the spathe (vs. usually less than length of spathe). It also differs in having orangish (rather than greenish white to lavender) berries.

The species may be confused with P. alticola and P. smithii. See those species for separation.

A noteworthy collection is Croat 66503, which has the veins on the lower leaf surface drying darker than the surface rather than paler, which is normally the ease. Collections from Costa Rica differ from those in Panama in having slightly smaller leaves with both the petioles and the blades shorter than those in Panama (petioles to 28 cm long and blades to 31 cm long in Costa Rica vs. petioles to 59 cm long and blades to 55 cm long in Panama). Nevertheless, the smaller leaves in Panama range down to only slightly larger than those in Costa Rica (with petioles as short as 32 cm long and blades to as small as 33 cm long). One collection from Guanacaste (Herrera 1473) is unusual in having more narrowly triangular blades with concave margins, narrower posterior lobes, a parabolic sinus, and a D-type style. However, it is otherwise similar, having the same dried stem characteristics and 1 ovule per locule. More collections are needed to determine if this entity is distinct from P. straminicaule.

This species perhaps also occurs in Colombia based on collections from Valle Department {Juncosa 2054) at 580 m and from Gorgonilla Island, Cauca Department (Killip & Garcta 33060). These collections differ from those in Panama in having blades with no obvious secretory ducts visible on the abaxial surface. In addition, the latter collection is from just 130 to 200 m elevation, substantially lower than where it is found in Panama.

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