PHILODENDRON ANTONIOANUM
PROTOLOGUE: Philodendron antonioanum , published in Annals of the Missouri Botanical Garden 84: 402 (1997).
Philodendron antonioanum Croat, sp. nov.
Planta hemiepiphytica; internodia brevia, 4–7 cm diam.; cataphylla rubra, acute 2-costata, persistentia ut fibrae tenues; petiolus 28–91 cm longus, obtuse complanatus adaxialiter; lamina ovata, 26–86 cm longa, 18–57 cm lata, nervis primariis lateralibus 5–6 utroque; inflorescentia 2; pedunculus 6–7 cm longus; spatha 15–16 cm longa; lamina spathae extus viridalba, intus alba suffusa rubella in dimidio inferiore; tubo spathae in superficibus ambabus marronino; pistilla 5-locularia; loculi 25–30-ovulati.
TYPE: Panama. Veraguas: vic. of Santa Fe, along road between Alto Piedra and Calovébora, 0.5 mi. N of Alto Piedra, on slopes of Cerro Tute, Parque Nacional Cerro Tute, 1030 m, 15 July 1994, Croat & Zhu 76909 (holotype, MO-4619868-9, MO-4619871-2; isotypes, B, CAS, COL, CR, F, GH, K, MEXU, MO, NY, PMA, SCZ, US, VEN). Figures 61–64.
DISTRIBUTION: C. Panama: Panama.
SPECIES DESCRIPTION:
Hemiepiphytic; larger stems drying reddish brown, smooth, and coarsely striate at nodes, smaller stems drying light yellow-brown, glossy, and finely longitudinally ribbed, finally dark brown and transversely finely cracked; internodes short, 4–7 cm diam., broader than long; roots to 30 cm long, numerous per node, drying reddish brown, weakly glossy, and somewhat ridged; cataphylls 35–39 cm long, sharply 2-ribbed, red, broadly sulcate abaxially, persisting as pale brown fibers densely clothing the entire apex of the stem with tiny fragments of reddish brown epidermis persisting among the fibers; petioles 28–91 cm long, 1.5–2 cm diam., subterete, obtusely flattened adaxially, weakly 1-ribbed near apex, broadly and obtusely sulcate, to 3.5 cm diam. near base, dark green (reddish brown when young), drying reddish brown and matte, surface moderately glossy, prominently striate-lineate throughout; blades broadly ovate, moderately coriaceous, bicolorous, semiglossy, 26–86 cm long, 18–57 cm wide (1.2–1.5 times longer than wide), margins broadly and sparsely undulate, upper surface drying dark brown to gray-brown, lower surface drying reddish brown; sinus hippocrepiform to obovate, 4–18 cm deep; midrib flat and slightly paler than surface, drying convex and darker than surface above, convex, sometimes tinged reddish, drying obtusely angular, grayish brown, and sparsely short pale-lineate below; basal veins 7 per side, with the first and second free to base, the third through sixth veins coalesced to 7 cm, posterior rib barely naked near the base, weakly curved; primary lateral veins 5–6 per side, departing midrib at a 40–50° angle, drying reddish brown below, obtusely and deeply sunken, concolorous, drying raised and somewhat darker above, convex, ± concolorous, drying concolorous, matte below; minor veins moderately distinct, drying prominulous above and below, arising from both the midrib and primary lateral veins, secretory canals appearing but not obvious below; “cross-veins” numerous, ± transverse.
INFLORESCENCE:
INFLORESCENCES 2 per axil; peduncle 6–7 cm long, 1.5 cm diam., magenta, conspicuously white-striate toward the apex; spathe 15–16 cm long, weakly constricted midway, weakly glossy, moderately coriaceous, drying reddish brown on both surfaces, acuminate at apex; spathe blade greenish white outside, white, tinged reddish in lower half inside; spathe tube inflated, dark maroon outside, to 7 cm long, 5.8 cm diam., dark maroon inside; spadix 15 cm long; pistillate portion 3.5–5 cm long in front, 3.3–3.7 cm long in back, 2–2.5 cm diam. at apex, 2.3–3 cm wide at base; staminate portion 9–11.7 cm long; fertile staminate portion gradually tapered toward apex; sterile staminate portion 2.5–2.6 cm diam.; pistils 3.2–3.5 mm long, creamy brown, ovary 5-locular, ca. 0.4 mm long, with parietal placentation; ovules 25–30 per locule, 2–3-seriate; funicle ca. 0.2 mm long, style 1 mm diam., similar to style type B; style apex flat, with small depressions; stigma 1.3–1.5 mm diam., 0.4 mm high, covering entire style apex; the androecium margins sharply 4–6-sided, 0.6–1.2 mm diam. at apex; sterile staminate flowers rounded to bluntly 4–6-sided, larger toward the base, 0.6–2.8 mm wide.
ECOLOGY:
Found in Tropical Lower Montane rain forest at 800 to 1200 m elevation. Flowering probably takes place in the early rainy season; two fertile collections have been seen, one with immature fruits in June and one post-anthesis in July.
ETYMOLOGY:
Named in honor of Thomas Antonio of the Chicago Botanic Garden, who was resident botanist in Panama for the Missouri Botanical Garden and who first collected the species in June 1980. The Latinized epithet antonioanum means “of Antonio.”
NOTES:
1. Philodendron antonioanum is a member of Philodendron sect. Philodendron subsect. Philodendron ser. Fibrosa. The species is distinguished by its red, sharply two-ribbed cataphylls, which persist as fibers; its subterete petioles longer than the blades; broadly ovate reddish brown drying blades with 5–6 primary lateral veins; and by the stout inflorescences with scarcely constricted spathes having the tube magenta on both surfaces.
2. Philodendron antonioanum is most easily confused with Philodendron tysonii, a species with which it may occur. Both species occur at higher elevations, and have subterete petioles longer than blades, large, ovate, glossy blades, and red or reddish cataphylls persisting as fibers. Philodendron tysonii differs in having mostly unribbed cataphylls and blades with usually 6–10 primary lateral veins and with the upper surfaces drying usually more or less blackened and smooth, in contrast to blades with 4–6 primary lateral veins and with upper surfaces drying gray-green with prominulous cross-veins as in Philodendron antonioanum. In addition, Philodendron tysonii has more prominently pedunculate inflorescences with green spathes, which are merely tinged red on the tube outside and are proportionately more slender and more constricted above the tube rather than being dark magenta on the tube and barely constricted above the tube as in Philodendron antonioanum. Finally, the species differ in the nature of ovules, with Philodendron tysonii having ovaries (5)6–8(9)-locular with subbasal placentation and (4)5–7 ovules per locule borne in an envelope, while Philodendron antonioanum has ovaries 5-locular with parietal placentation and about 30 ovules per locule not borne within an envelope.
STORY:
STORY TITLE: A philodendron named for the botanist who first collected it in Panama
Philodendron antonioanum grows in the Tropical Lower Montane rain forest of central Panama, where it is known only from the slopes of Cerro Tute and from El Copé, between about 800 and 1200 meters. Thomas Antonio, of the Chicago Botanic Garden and then resident botanist in Panama for the Missouri Botanical Garden, first collected it in June 1980. Croat and Zhu gathered the type on the slopes of Cerro Tute, in Parque Nacional Cerro Tute, in July 1994, and Croat named the species for Antonio when he described it in 1997.²
In the field the plant can be taken for Philodendron tysonii, with which it may grow. Both are hemiepiphytes with subterete petioles longer than their large, glossy blades and with red, fibrous cataphylls. What sets antonioanum apart is in the detail: its cataphylls are sharply two-ribbed, its blades carry only five or six primary lateral veins, and its stout, scarcely constricted spathes are magenta on the tube both inside and out, where tysonii keeps slenderer, greener, more strongly constricted inflorescences.²
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Philodendron antonioanum
2. Annals of the Missouri Botanical Garden 84: 402 (1997) — protologue.
3. iNaturalist: Philodendron antonioanum
Additional photos from iNaturalist by ramon_d