PHILODENDRON BILLIETIAE
PROTOLOGUE: Philodendron billietiae , published in Novon 5: 24 (1995).
Philodendron billietiae Croat, sp. nov. TYPE: French Guiana. National Hwy. 2, Cayenne–Regina, vic. km 93, 100–150 m, 4°18′N, 52°10′W, Croat 74321 (holotype, MO 4343643–5; isotypes, B, BBS, BR, BRG, CAS, CAY, CM, F, G, GH, INPA, K, M, MG, NY, P, US, VEN). Figures 1–4.
Planta hemiepiphytica; internodia brevia, usque 2.5–5 cm diam.; petiolus subteres, 25–57 cm longus, pallide aurantiacus-flavus vel viridi-flavus; lamina plus minusve anguste triangularis et sagittata, 30–85 cm longa, 8.1–21 cm lata; nervis lateralibus primariis 3–5 utroque; pedunculus 9.4–27 cm longus; spatha 17.5–18.5 cm longa, extus viridis; lamina intus alba; tubus intus purpurascens; spadix 16.5–18 cm longus; ovaria 6–11 locularia cum ovulis plus quam 10 in quoque loculo; affinis Philodendron acutato Schott sed internodis proportione brevioribus, petiolo in vivo flavido vel ochraceo versus constanter viridi, lamina proportione angustiore basique lobis 35–40° versus 60–75° divergentibus differt.
DISTRIBUTION: Guianas, Brazil (Pará): Brazil North, French Guiana, Guyana.
DISTRIBUTION NOTE: iNaturalist: Amapá.
SPECIES DESCRIPTION:
Appressed-climbing hemiepiphyte, sometimes on rocks; stems about 1 m long, sometimes longer; internodes shorter than broad, 2.5–5 cm diam., light brown with irregular, weak, reticulate to mostly transverse fissures, turning yellow-brown; petiole scars to 4.5 cm diam.; cataphylls sharply D-shaped near apex, otherwise terete and unribbed or sometimes bluntly 2-ribbed, green to pale orange (sometimes brown, orange at base) or reddish, promptly caducous; roots moderately few, stout, ca. 5 mm diam., purplish brown, drying smooth, semiglossy, the epidermis often fissured; leaves usually clustered near the end of the stem, with erect spreading petioles and pendent blades; petioles broadly spreading, 25–57 cm long, averaging 40 cm long, broadly sulcate at base, obtusely flattened toward the apex, weakly angular near the apex, sheathed 4–8 cm at the base, firm, olive green to golden-yellow, pale yellow-orange or greenish yellow, when fresh, somewhat asperous and rather densely purplish-lineate, drying light yellow-brown to dark brown, typically closely fissured; blades pendent, narrowly triangular to narrowly ovate-triangular to oblong-triangular, 30–85 cm long, 8.1–21 cm wide (averaging 52 × 15 cm), 2.7–4 times longer than wide, averaging 3.4 times longer than wide, broadest at the base or near the petiole attachment, sometimes weakly constricted above the petiole attachment, 0.85–1.4 times as long as the petioles (averaging 1.07 times longer than petioles), moderately coriaceous, dark green and semiglossy above, much paler and matte to weakly glossy below; the margins often weakly undulate, hyaline or reddish; posterior lobes directed at about 170° from the midrib (the two lobes separated by an angle of 35–40°), sometimes directed up slightly at an angle to the midrib, 8–22 cm long, 3–10 cm wide, about twice as long as wide; sinus much longer than wide, acute at apex, usually barely naked along the margin, but sometimes weakly naked up to 2.5 cm (the leaf tissue merging almost imperceptibly with the posterior rib); midrib flat to very broadly raised and paler (sometimes orange-yellow) with purplish dots above, narrowly raised and convex, yellow-brown to yellow-red or yellow-green below; primary lateral veins 3–5, widely spaced and usually not prominent, weakly sunken to flat and yellow-green above, convex to weakly raised and sometimes reddish to purplish below, arising at 70–105° angle, mostly at nearly 90° angle, sometimes prominently down-turned at the midrib, sometimes splayed out at the midrib; minor veins numerous, moderately distinct when fresh, weakly raised above, flat and distinctly visible below, drying prominulous on both surfaces, with alternate veins frequently turned to join another minor vein just before the margin; cross veins inconspicuous; young leaves reddish.
ECOLOGY:
Found in tropical rainforest at 140 to 340 m elevation according to the protologue; the seven gatherings cited there with an elevation, the type (100–150 m) among them, range from 5 to 670 m. A plant creeping over rocks in full sun is shown in Fig. 1 of the protologue.
ETYMOLOGY:
Named in honor of Frieda Billiet, a Belgian botanist at the National Botanic Garden of Belgium (Meise), who found living plants of this species in French Guiana in 1981 and introduced them to cultivation at Meise. The Latinized epithet billietiae means “of Billiet.”
STORY:
STORY TITLE: Cultivated in Belgium for fourteen years before it had a name
Frieda Billiet collected living plants of this species from lowland rainforest in French Guiana in 1981 and brought them into cultivation at the National Botanic Garden of Belgium in Meise, where they grew unnamed for well over a decade. It was not until 1995 that Thomas Croat formally described the plant as new, naming it Philodendron billietiae for the collector whose plants had already been growing at Meise for fourteen years.²,⁵
A 2023 survey of floral scent chemistry across nine French Guiana Philodendron species found that Philodendron billietiae produces an unusually simple perfume for the genus: more than ninety-three percent of it is a single compound, 4-vinylanisole.⁴
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Philodendron billietiae
2. Novon 5: 24 (1995) — protologue.
3. iNaturalist: Philodendron billietiae
5. Billiet F. 2005. The collections of Araceae at the National Botanic Garden of Belgium. Aroideana 28: 113–129
Additional photos by Patrick Blanc
Additional photos by David Scherberich
Additional photos from iNaturalist by carstonchance, Robin Heymans, simba20a, Julien Piolain, Lilian Eprendre, Pierrot F., Sébastien SANT and Wim.Jacobs