PHILODENDRON ALBISUCCUS
PROTOLOGUE: Philodendron albisuccus , published in Annals of the Missouri Botanical Garden 84: 393 (1997).
Philodendron albisuccus Croat, sp. nov.
Planta hemiepiphytica; internodia 2–3 cm longa, 2.8 cm diam.; succus albus, in sicco calcareus; cataphylla leviter 1-costata vel acute 2-costata, persistentia ut fibrae tenues, pallidae; petiolus usque 51–72 cm longus, subteres, leviter complanatus basi usque ad medium; lamina anguste ovata, cordata basi, 50–66 cm longa, 24.5–42 cm lata; inflorescentia 1; pedunculus (3.7)7–12 cm longus; spatha 13.5–14.5 cm longa, extus viridis, intus pallide flaviviridis; pistilla 5–6-locularia; locules cum 18–20 seminibus; baccae albae.
TYPE: Panama. Darién: Parque Nacional del Darién, middle slopes on W side of Cerro Pirre, 800–1500 m, 7°56′N, 77°45′W, 29 June 1988, Croat 68940 (holotype, MO-3589989; isotypes, B, COL, K, PMA, US). Figures 41–43.
DISTRIBUTION: Colombia to Panama: Colombia, Panama.
SPECIES DESCRIPTION:
Hemiepiphytic; stem ± appressed-climbing, to 75 cm long, to 2.8 cm diam., sap chalky white; internodes short, usually sparsely covered with cataphyll fibers, 2–3 cm long, 2.8 cm diam., dark green; roots brownish, few per node, epidermis smooth to flaking and peeling; cataphylls thin, to 40 cm long, weakly 1-ribbed to sharply 2-ribbed, sparsely short-lineate, persisting as thin, pale fibers at upper nodes, then deciduous; petioles 51–72 cm long, 3–7 mm diam., erect-spreading, subterete, dark green, weakly flattened from near base to middle, obtusely sulcate at the base adaxially, surface semiglossy; blades narrow ovate, subcoriaceous, splitting, long-acuminate at apex (the acumen inrolled), cordate at base, 50–66 cm long, 24.5–42 cm wide (1.6–2 times longer than wide), (ca. about equal in length to petiole), broadest just below point of petiole attachment, upper surface dark green, semiglossy, lower surface semiglossy, moderately paler, drying yellow-green; anterior lobe 37–48(54.5) cm long, 23.1–27.4(42.4) cm wide (4.2–4.4 times longer than posterior lobes); posterior lobes 8.5–11.5(16.5) cm long, 9.7–12(18.5) cm wide; sinus hippocrepiform; midrib flat, concolorous above, bluntly acute, slightly paler than surface below; basal veins 3–5 per side, with 1 free to base, third and higher order veins coalesced 0.5–2 cm long, the fifth and sixth veins sometimes coalesced to 5 cm long; posterior rib naked, raised; primary lateral veins (4)6–7(8) per side, departing midrib at a 60–65° angle, sunken above, raised to convex below; interprimary veins darker than surface; minor veins arising from both the midrib and primary lateral veins; lesser veins obscure to visible.
INFLORESCENCE:
Inflorescences 1 per axil; peduncle (3.7)7–12 cm long, 3–3.5 mm diam., pale green; spathe semiglossy, 13.5–14.5 cm long (1.2–1.8 times longer than peduncle), weakly constricted above the tube, green throughout, pale yellow-green (greenish brown post-anthesis) within; spathe tube densely short pale lineate outside, 5–7 cm long; spadix 12 cm long at anthesis; pistillate portion 4.3 cm long in front, 3 cm long in back, 8 mm diam. midway, 7 mm diam. at apex; staminate portion to 10 cm long; fertile staminate portion to 9 mm diam. toward apex, somewhat narrower just above the sterile portion, to 5 mm diam. 1 cm from apex; sterile staminate portion 9 mm diam.; pistils 6–6.3 mm long, 1.8–2.5 mm diam., ovary 5–6-locular, with axile placentation; ovules 2-seriate, style similar to style type B; style apex flat; stigma subdiscoid. Infructescence 6.4 cm long, 3 cm diam.; berries white; seeds 18–20 per locule.
ECOLOGY:
Found at 800–1400 m elevation in premontane rain forest
ETYMOLOGY:
From Latin albus, “white,” and succus, “sap” or “juice.” Although the original description does not explicitly explain the epithet, it refers to the sap in all cut parts of the plant, which promptly turns white and chalky upon exposure to air — the character that most distinguishes the species.
NOTES:
1. Flowering in Philodendron albisuccus is poorly known with a flowering collection seen in October, immature fruits in June, and nearly mature fruits in July.
2. Philodendron albisuccus is a member of Philodendron sect. Philodendron subsect. Cardiobelium ser. Albisuccosa. The species is characterized by its short internodes; thin, obscurely one-ribbed cataphylls, which persist at the upper nodes as thin, pale fibers; subterete petioles (about as long as the blades); the narrowly ovate, moderately cordate blades with a hippocrepiform sinus; and especially by the sap in all the cut plant parts, which promptly turns white and chalky upon exposure to air. Only one other species in Panama, Philodendron cretosum Croat & Grayum, has chalky sap. Though both species have chalky sap (a rare feature for Philodendron) and 18–20 ovules per locule, I do not believe them to be closely related as they show no other features in common. Philodendron cretosum differs most particularly in having slender oblong-lanceolate blades that are 5.1–8.3 times longer than wide (vs. 1.6–2 times longer than wide for Philodendron albisuccus). Philodendron albisuccus also has the much longer petioles (51–72 cm long vs. 10–23 cm long for Philodendron cretosum), more broadly spreading primary lateral veins (60–65° vs. 25–45° angle for Philodendron cretosum). In addition, Philodendron albisuccus has minor veins more distinct than those of Philodendron cretosum.
3. The species is superficially similar to Philodendron alticola Croat and Philodendron straminicaule Croat & Grayum, both of which have blades of similar size, shape, and color upon drying. Both differ by having the inner surface of the spathe red rather than green.
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Philodendron albisuccus
2. Annals of the Missouri Botanical Garden 84: 393 (1997) — protologue.