PHILODENDRON CRASSISPATHUM

PROTOLOGUE: Philodendron crassispathum , published in Annals of the Missouri Botanical Garden 84: 425 (1997).

Philodendron crassispathum Croat & Grayum, sp. nov.

Type: Panama. Chiriquí: Cerro Colorado, above San Felix along mining road, 18–27 mi. off Pan-American Hwy., above Chame (turnoff to Escopeta), 1200–1500 m, 8°35'N, 81°50'W, 12 Mar. 1976, Croat 33150 (holotype, MO-2395067; isotypes, B, F, K, PMA, US).

DISTRIBUTION: C. Costa Rica to W. Panama: Costa Rica, Panama.

DISTRIBUTION NOTE: iNaturalist: Alajuela, Guanacaste, Puntarenas.

SPECIES DESCRIPTION:

Hemiepiphytic, sometimes terrestrial; stem appressed-climbing or scandent, creeping, becoming matte and gray, smooth when fresh, sap watery, spicy-scented, leaf scars conspicuous, 9–20 mm long, 2–3.5 cm wide; internodes drying conspicuously wrinkled, epidermis weakly glossy, 1.5–8 cm long, (1–1.8)2.5–3.5 cm diam., usually broader than long, dark green, epidermis brownish and cracking; roots dark brown, smooth upon drying, elongate, 3–50 cm long, 1–3 mm diam., few per node; cataphylls fleshy, 8.5–24 cm long, sharply 2-ribbed, green to dark green, dark green short-lineate, drying yellowish brown to pale green, persisting semi-intact at upper nodes then eventually fibrous then deciduous. LEAVES erect-spreading to spreading; petioles 20–31(48) cm long, 5–19 mm diam., subterete, somewhat spongy, sometimes tinged brown near apex, obtusely flattened with obtuse medial rib adaxially, convexly rounded abaxially; blades broadly ovate-cordate, very coriaceous, acuminate at apex (the acumen inrolled, 2–5 mm long), cordate at base, 14–29 cm long, 11–24 cm wide (1–1.56 times longer than wide), broadest at or near the middle, margins hyaline, whitish or reddish, tightly curled under when dried, upper surface dark green, glossy, drying semiglossy to matte, lower surface paler, drying greenish gray to yellowish green to brownish, drying semiglossy to matte; anterior lobe 10–25 cm long, 11–33 cm wide (1.6–2.5 times longer than posterior lobes); posterior lobes 4.5–10 cm long, 5–16.5 cm wide, obtuse to rounded; sinus spathulate to hippocrepiform; midrib flat to very broadly convex, drying yellowish green, paler than surface above, weakly convexly raised, paler than surface below; basal veins 3–4(6) per side, with 0–1 free to base, most of the remainder coalesced 1–2.5(4.4) cm, flat above, weakly raised below; posterior rib not naked if present; primary lateral veins 4–6 per side, departing midrib at a 40–70° angle, ± straight to the margins, flat, paler than surface, drying obscure above, raised and paler below; interprimary veins obscure above, weakly visible below; minor veins etched above, visible and darker than surface below, arising from midrib only.

INFLORESCENCE:

INFLORESCENCES shorter than leaves, 1 per axil; peduncle 3.5–7 cm long, 1–2.5 cm diam. (dried), terete, drying brown; spathe fleshy, (6.8)10–14 cm long, 4.5–10 cm diam., not at all constricted, ± ellipsoid, bluntly acute to rounded at apex, the walls to 1 cm or more thick midway; spathe blade red outside, red to white inside; spathe tube green, sometimes yellowish to orange-red outside, violet-purple to red inside; spadix (6.5)9–14 cm long; pistillate portion grayish to golden-yellow, cylindrical to slightly ellipsoid, 1.5–7 cm long, 10–25 mm diam. throughout, with 13–15 flowers visible per spiral; staminate portion 5–9 cm long; fertile staminate portion white with orange-brown droplets, cylindrical, weakly constricted above sterile portion, tapered toward apex, 15–23 mm diam. throughout, broader than pistillate and sterile portions, 22–27 flowers per spiral; sterile staminate portion 17–24 mm diam.; pistils 4–4.5 mm long, 4–4.5 mm diam.; ovary 6–7-locular, with axile placentation; ovules 7–10 per locule, 0.6–1 mm long, 0.3 mm diam.; funicles with free portion ca. 1 mm long, the remainder loosely fused to the wall of the locule; style similar to style type D, button-like and concave on drying, 1.3–2 mm diam., the margins pale; androecium margins irregular, 0.6–1.3 mm long; sterile staminate flowers ± globose, 1.4–2.2 mm long. INFRUCTESCENCE erect; pistillate spadix 4.5–5 cm long, 4 cm diam.; berries green becoming orange to whitish; pericarp white; mesocarp yellowish white; seeds yellow-orange, 2.9–3.5 mm long, 0.7–1 mm diam.

ECOLOGY:

Found in premontane rain forest and tropical lower montane rain forest life zones, at 1100–2600 m elevation. Flowering takes place mainly from February to April and in August, during the dry season and early rainy season, with mature fruit collected only from January to March, suggesting fruits take nearly a year to develop.

ETYMOLOGY:

Although the original description does not explicitly explain the name, it likely refers to the unusually thick spathe walls: from Latin crassus, “thick,” and spatha, “spathe.”

NOTES:

1. Philodendron crassispathum is a member of Philodendron sect. Calostigma subsect. Macrobelium ser. Ecordata. The species is characterized by its high elevational habitat, fleshy, deciduous, sharply two-ribbed cataphylls and somewhat spongy petioles.

2. Philodendron crassispathum is most closely related to Philodendron brenesii, which differs in having narrowly ovate blades with a narrow V-shaped sinus and mostly free basal veins, and a comparatively thin spathe clearly constricted above the tube portion. In contrast, Philodendron crassispathum has blades with a typically spathulate to hippocrepiform sinus and a usually obvious posterior rib.

REFERENCES:

1. Plants of the World Online, Royal Botanic Gardens, Kew — Philodendron crassispathum

2. Annals of the Missouri Botanical Garden 84: 425 (1997) — protologue.

3. iNaturalist: Philodendron crassispathum

Additional photos from iNaturalist by Nate Hartley, J Esteban Jiménez, Trevor Van Loon, Rose Zappa, ramon_d, Ethan Beaver, Edgar Abel Toribio Pèrez, Luke Berg, mdahms, Stefan Dominik Brändel, mdoliveira and Michelle Goerdel