Philodendron grayumii Croat, sp

Philodendron grayumii Croat, sp. nov.

TYPE: Panama. Bocas del Toro: Fortuna Lake area, Fortuna--Chiriquí Grande, 0.3 km N of Continental Divide, 970 m, 8E43'N, 82E17'W, 27 June 1994, Croat & Zhu 76524 (holotype, MO--4619417--20; isotypes, AAU, B, CAS, CM, CR, COL, DUKE, F, GH, K, M, MEXU, NY, PMA, S, SCZ, SEL, TEX, US). Figures 209--215.

Planta hemiepiphytica; internodia 1--10 cm longa, (2.5)3.5--7 cm diam.; cataphyllum 11--26 cm longa, incostata vel leniter 1-costatata, demum decidua aut acute complanta vel 2-costata; petiolus 40--97 cm longus, subteres, obtuse planatus prope apicem; lamina ovata vel late ovate, (31)50--73 cm longa, 24--44(58) cm lata; cordata basi; nervis basalibus 4--5(6) utroque; nervis lateralibus I 4--6 utroque; inflorescentia 1--5 per axillam; pedunculus (2)4--6 cm longus; spatha (11)13--16(18) cm longa, extus pallide viridis vel virens, albida vel pallide flava versus apicem, minimum interdum maculata purpurea-violacea, tubo spathae marronino vel rubro intus; pistilla 7--8-locularia; loculi (2)3--4(5)-ovulatii.

Hemiepiphytic, appressed-climbing; internodes semiglossy to matte, 1--10 cm long, (2.5)3.5--7 cm diam., dark green to gray-green or tannish gray, drying brown to yellow-brown or reddish brown, epidermis closely ridged or fissured, sometimes peeling; roots usually 1--2 per node, ca. 3--4 mm diam., drying dark reddish brown; cataphylls thick, somewhat spongy, 11--26 cm long, unribbed to weakly 1-ribbed near apex or sharply flattened to sharply 2-ribbed, (ribs close), green, sometimes weakly maroon spotted, often persisting intact for a short time then deciduous, intact; petioles 40--97 cm long, 1--1.5 cm diam., subterete, firm, dark to medium green, obtusely and often weakly flattened near apex, sometimes weakly ribbed near apex adaxially, surface semiglossy, weakly and densely short pale green lineate, drying yellowish brown to dark brown, smooth to finely striate, sheath 6--15 cm long; blades ovate to broadly ovate, coriaceous to subcoriaceous, moderately bicolorous, semiglossy, acute to gradually or abruptly acuminate at apex, deeply cordate at base, (31)50--73 cm long, 24--44(58) cm wide ((0.7)1--1.9 times longer than wide), three-fourths as long as to somewhat longer than the petiole, upper surface dark green, drying dark brown toyellow-brown or grayish brown, semiglossy, lower surface conspicuously paler, drying yellow-brown, weakly to semiglossy; anterior lobe (25)31--49(60) cm long, (13)24--32(42) cm wide (2.3--4.6(8) times longer than posterior lobes), margins broadly rounded, sometimes sinuate; posterior lobes rounded to narrowly rounded, sometimes overlapping, (6)9--13(17) cm long, 12--18(22) cm wide; sinus hippocrepiform to oblong spathulate, obovate, or sometimes triangular to parabolic, rounded to narrowly rounded, (8)10.5--13 cm deep; midrib flat to broadly raised above, paler than surface above, convex to obtusely acute and sometimes purplish spotted below; basal veins 4--5(6) per side, with 1--2 free to base, third and higher order veins coalesced 3--6(8) cm long; posterior rib usually not naked, rarely naked for 1.5 cm; primary lateral veins 4--6 per side, departing midrib at a (45)55--70(75E) angle, ((45)55--70(75E) angle), downturned and splayed out when joining midrib, obtusely to narrowly sunken and paler than surface, sometimes weakly raised, drying weakly ridged near the midrib above, convex and paler than surface, sometimes reddish below; minor veins moderately indistinct, drying weakly prominulous (surface often with minute purplish raised areas seen on high magnification), arising from both the midrib and primary lateral veins, secretory ducts appearing as intermittent lines (less conspicuous on highland forms); INFLORESCENCES 1--5 per axil; peduncle (2)4--6 cm long, 1--1.5 cm diam., pale green, finely short-lineate; spathe (11)13--16(18) cm long, 2-3 cm diam. (2.1-2.6(3.5) times longer than peduncle), weakly constricted more or less above the middle, pale to medium green, sometimes whitish to pale yellowish toward apex, often tinged or spotted violet-purple throughout, especially near base, sometimes green dorsally with only the front edges of tube maroon, margins white, outer surface drying reddish brown throughout inside, violet-purple to maroon in lower one-half to two-thirds, especially in lower half; spathe tube 7--8.5 cm long, 2--3.6 cm diam., maroon to red, with pale lineations extending onto blade area inside; spadix sessile; cylindrical, 9.5--16 cm long, broadest above the middle or below the middle; pistillate portion pale green, cylindrical to weakly tapered toward the apex, 3.3--3.5 cm long, 4.6 cm long in front, 3.2--3.5 cm long in back, 9--20 mm diam. throughout; staminate portion 6.3--12.5 cm long; fertile staminate portion creamy white, cylindrical, 1--1.4 cm diam. at base, 1--1.4 cm diam. at middle, 8--10 mm diam. ca. 1 cm from apex, broadest at the base or at the base, broader than or as broad as the pistillate portion, sterile staminate portion usually not detectable; pistils 1.4--1.9 mm long, 0.8--1.1 mm diam.; ovary 7--8-locular, 1--1.4 mm long, 0.8--1 mm diam., walls thin and membranous, locules 1--1.3 mm long, 0.3--0.4 mm diam., ovule sac sometimes present, to 0.8 mm long, with sub-basal placentation; ovules (2)3--4(5) per locule, 2-seriate, contained within transparent, gelatinous ovule sac, 0.3--0.5 mm long, usually as long as funicle; funicle 0.2--0.3 mm long, (can be pulled free to base), style 0.5 mm long, 1.2 mm diam., similar to style type B; style apex sloping; stigma brushlike, sometimes cupullate, subdiscoid, unlobed, sometimes truncate or weakly domed, 0.9--1.3 mm diam., 0.2--0.6 mm high, covering entire style apex; the androecium truncate, prismatic, oblong, margins irregularly 4--6-sided, 0.9 mm long, 1.1 mm diam. at apex; thecae cylindrical to weakly ellipical, 0.3--0.4 mm wide, more or less parallel to one another; sterile staminate flowers trapezoidal to 4--6-sided, 1.1 mm long, 1.3 mm wide. INFRUCTESCENCE with peduncle to 11.5 cm long; spathe to 26 cm long, pistillate spadix to 13.5 cm long, 2.5 cm diam.; staminate spadix to 13.5 cm long; berries pale ochraceous, 3--3.3 mm long; seeds 1.9--2 mm long, 0.7--1 mm diam. PRE-ADULT petioles, sheathing throughout; blades oblong, subcordate, 26--31 cm long, 9--13 cm wide.

Flowering in Philodendron grayumii apparently occurs primarily in the rainy season (March as well as June and September), but also in the late dry season. Post-anthesis inflorescences have been collected in March as well as June through August and November. Immature fruits are known from June and November.

Philodendron grayumii ranges from Costa Rica to central Panama from sea level to 1630 m elevation in Premontane wet forest, Tropical wet forest, and Premontane rain forest life zones, as well as Premontane wet forest transition to Tropical moist forest.

Philodendron grayumii is a member of P. sect.

Calostigma subsect. Macrobelium ser. Macrobelium. This species is characterized by its yellow-brown drying stems, cataphylls deciduous intact, more or less ovate blades drying yellow-brown with the basal veins scarcely or not at all united into posterior ribs and rarely naked on the sinus, and primary lateral leaf veins splayed out, somewhat ridged and downturned near the midrib. The spathe is often tinged reddish to purplish outside and dark red to maroon in the tube within.

This species is a polymorphic one, especially in the nature of the resin canals in the leaves and the number of inflorescences per axil. Collections from near sea level in Limón Province of Costa Rica (Grayum 8467, 8469) are unusual in lacking any clearly visible secretory ducts (normally easily visible at least on the dried lower leaf surfaces).

Philodendron grayumii may be confused with P. edenudatum and the two may prove to be conspecific. Philodendron edenudatum differs in having proportionately longer leaf blades (1.8--2.1 times longer than broad) and proportionately shorter petioles (0.77--0.89 times as long as the blades).

Philodendron grayumii may also be confused with P. ferrugineum. The latter, occurring principally in the Canal Area, shares with P. grayumii brownish-drying blades with the basal veins usually not at all or only weakly naked. Philodendron ferrugineum differs in having generally shorter internodes, larger cataphylls (26--48 versus 11--26 cm long), typically much larger, more coriaceous blades drying reddish brown (rather than yellowish brown), and minor veins usually drying markedly longitudinally raised but interrupted, giving the leaf surface a markedly bumpy, irregular and uneven appearance.

Also perhaps confused with P. grayumii is P. dodsonii which has dried leaf blades of a similar yellowish brown color. The latter species differs in having conspicuously naked posterior ribs, blades drying matte on the upper surface and lacking any obvious secretory ducts on the lower surface.

Perhaps also to be confused with P. grayumii is P. aromaticum, which has similarly cordate blades that may dry a similar color and also has deciduous cataphylls. The latter species is distinguished by being a shorter-stemmed canopy epiphyte, and by having spongy petioles, and proportionately more elongated usually more gray-drying leaf blades (usually more than 1.7 times longer than wide) with the naked portion of the posterior ribs much longer (usually 2.5--5 cm long).

A noteworthy collection is Croat 67525 which is somewhat intermediate between P. grayumii and P. edenudatum. It has narrowly ovate leaf blades about 1.6 times longer than wide, mottled petioles and lower midribs, and relatively small (possibly immature) inflorescences (to 13 cm long). In these characters, the specimen is closest to P. edenudatum, but it has prominent secretory ducts visible on the lower blade surface, and two inflorescences per axil, features not known in P. edenudatum. In addition, the blades dry dark brown. In this latter regard, this collection differs from both P. grayumii and P. edenudatum. It perhaps represents a new species although it is being included with P. grayumii for now.

Another noteworthy collection is Croat & Zhu 76613, the only collection from east of the Canal Area. It is unusual in having the cataphylls semipersistent as fibers, rather than deciduous while still intact. This may prove to reprsent a different taxon.

A sterile collection (Croat 66712) is noteworthy in having stems that dry smoother, darker reddish brown and semiglossy, much glossier petioles than those of P. grayumii and blades that dry more coriaceous, glossier, and with the minor veins prominulous on both surfaces. It might represent another new species, but is tentatively included with this species.

The new species is named in honor of Michael H. Grayum, a colleague and aroid specialist, whose excellent collections of Araceae from Costa Rica and Panama have played an important role in this revision. He has collected the only Costa Rican material of the species.

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Additional specimens examined.

COSTA RICA. Limón: along road between Puerto Viejo de Talamanca and Manzanillo, vic. of Punta Cocles, ca. 5 m, 9E38'N, 82E43'W, 5 m, Grayum & Sleeper 4302 (CR, MO); 10--20 m, 10E38--39'N, 82E40--44'W, Grayum 3637 (MO); Piuta, ca. 1.5 km NW of Puerto Limón along highway to Portete, 5 m, 10E01'N, 83E03'W, Grayum & Hammel 8467 (MO), 8469 (MO). PANAMA. Bocas del Toro: Fortuna--Chiriquí Grande, 1.6 mi. N of Continental Divide, 770-790 m, 8E45'N, 82E17'W, Croat 76456 (AAU, CM, MEXU, MO, NY, OOM); 1.2 mi. N of Divide, 5.3 mi. N of Fortuna Dam, 910 m, 8E44'N, 82E17'W, Croat 60476 (AAU, CR, MO, PMA), 1170 m, Croat 66653A (MO); 5.8 mi. N of Fortuna Lake, 600 m, 8E45'N, 82E18'W, Croat 66794 (B, CAS, CM, COL, CR, F, K, L, MEXU, MO, NY, PMA, US, WIS); along Continental Divide (4.5 mi. N of middle of bridge over Fortuna Lake), 1170 m, 8E44'N, 81E17'W, Croat 66712 (MO); Gualaca--Chiriquí Grande, 1.6 mi. N of Continental Divide, 850 m, 8E48'N, 82E13'W, Croat 74933 (MO); 4.2 mi. E of Chiriquí Grande, ca. 0 m, 8E55'N, 82E09'W, Croat 66814 (MO, TEX); Station Milla 7.5 on Changuinola--Almirante Railroad, <100 m, Croat 38105 (B, F, K, MO, NY, PMA, US); Cerro Colorado, 6.5 mi. W of Chame, 1630 m, 8E35'N, 81E50'W, Croat 69164 (MO); Chiriquí Grande, Palo Seco--El Guayabo, km 112, Gordon 344 (PMA). Chiriquí: Gualaca--Chiriquí Grande, 4 mi. N of bridge over Fortuna Lake, 1200 m, 8E46'N, 82E16'W, Croat 68026 (CAS, CR, DUKE, F, G, MO, QCA, TEX, W); 1170 m, 8E44'N, 81E17'W, Croat 66712 (CAS, K, L, MEXU, MO, PMA); Río Hornito, ca. 0.5 km S of Centro de Científicos, 8E45'N, 82E18'W, Croat 76420 (CM, MO); 8.4 mi. beyond Los Planes de Hornito, 1130 m, 8E44'N, 82E14'35"W, Croat 67869 (DUKE, MO, NY, PMA). Coclé: 4.5 mi. N of El Cope, 580-740 m, Croat 67525 (C, ENCB, MO, P, VDB); 4.1 mi. N of El Copé, 770--680 m, 8E39'N, 80E36'W, 74840 (CM, CR, MO, PMA, US); 5--6 mi. N of El Copé, 600--800 m, 8E38'N, 8E35'W, Croat & Zhu 77202 (IBE, M, MO, MY, W); Llano Grande--Coclecito, 4.3 mi. N of stream in Llano Grande, 330 m, Croat 49235 (CM, MO). Veraguas: vic. of Santa Fe, 5 mi. past Escuela Agrícola Alto de Piedra, 670 m, 8E33'N, 81E08'W, Croat 66922 (BR, COL, M, MO); 66969 (AAU, MO, NY, OOM, PMA).