PHILODENDRON CREMERSII
PROTOLOGUE: Philodendron cremersii , published in Novon 4: 211 (1994).
Philodendron cremersii Croat & Grayum, sp. nov. Type: French Guiana. Montagnes de Kaw, along road to Montagne Favard, in vicinity of junction to Fourgrassie, 04°38′N, 52°17′W, 200 m, Croat 74336 (holotype, MO-4343662; isotypes, B, CAY, F, K, MG, NY, P, US, VEN).
DISTRIBUTION: French Guiana: French Guiana.
SPECIES DESCRIPTION:
Hemiepiphyte, on tree trunks near the ground. Stems sometimes trailing when preadult, appressed-climbing when adult. Internodes 1–9(17) cm long, (0.5)1–1.5 cm diam., dark green to bluish green, matte to weakly glossy, flattened on one side, drying light yellow-brown to medium reddish brown, drying narrowly ridged (sometimes irregularly so on juveniles). Petioles to 27 cm long, sheathed to within 1.2–1.7 cm of the base of the blade on adult plants (to beyond the base of the blade on juveniles); sheath narrow (the sides ca. 5 mm high), to 10 mm or more wide when flattened, erect-incurled, overlapping at base, erect and incurled toward apex, emarginate and free-ending at apex, dark green and matte, the surface drying finely striate. Blades somewhat inequilateral, one side 0.5–4.3 cm narrower, ± elliptic, rarely narrowly oblanceolate, 6.5–21 cm long, 6.5–13 cm wide when young, usually narrowly oblanceolate, 30–50.5 cm long, 9–20 cm wide, ca. 3 times longer than wide (rarely as little as 1.8 times longer than wide), acuminate at apex, equilateral or only slightly inequilateral and acute to narrowly rounded at base, subcoriaceous, dark green and subvelvety matte when young, becoming weakly glossy when mature, moderately paler and semiglossy below (matte when juvenile), becoming semiglossy, usually drying dark brown above, lighter brown below; margins broadly undulate; midrib obtusely sunken and concolorous to slightly paler above, narrowly raised below (sometimes convex on juveniles) and paler below. Primary lateral veins to ca. 20 per side on adults (5–9 on juveniles), arising at 55–80° angle (45–55° on juveniles), weakly arcuate, weakly quilted-sunken above, weakly raised to convex and paler below, sometimes weakly pleated, drying darker than surface below. Minor veins sparse, moderately distinct below, drying weakly raised and somewhat undulate with rather prominent oblique cross veins.
INFLORESCENCE:
Inflorescences 1–2 per axil. Peduncle to 3 cm long, largely hidden by the spathe. Spathe 14–17 cm long, slightly constricted above the tube. Spathe tube medium green outside, blade pale green to whitish, the entire inner surface greenish white. Spadix 11–16.5 cm long; female portion of spadix pale green, to 5 cm long in front, 4.7 cm long in back, to 2 cm diam. midway, 1.8 cm diam. at apex, 1.7 cm diam. at base.
ECOLOGY:
Hemiepiphyte, on tree trunks near the ground.
ETYMOLOGY:
Named in honor of Georges Cremers, a long-time researcher at ORSTOM in French Guiana. He has made many excellent collections of Araceae, including the first collection of this species.
NOTES:
1. Planta hemiepiphytica; internodia 1–9(17) cm longa; petiolus (6)13–27 cm longus, vaginatus usque 1.2–1.7 cm infra laminam; vagina erecta; lamina plus minusve elliptica, 30–50.5 cm longa, 9–20 cm lata, nervis primariis lateralibus ca. 20 utroque; pedunculus usque 3 cm longus; spatha 14–17 cm longa; spadix 11–16.5 cm longus; parte pistillata usque 5 cm longa.
2. Plants believed to represent Philodendron cremersii are also relatively common around Eaux Claires near Saul in central French Guiana, but were seen only in sterile and probably juvenile condition on the lower trunks of trees in the forest understory. The Saul material (Croat 74165 and 74234) differs in having blades that are subvelvety above and matte below (drying gray-green above, slightly yellow-green below, with the epidermal cells sunken on both surfaces), in contrast to weakly glossy for the fertile collections seen in the Montagnes de Kaw. It is likely that these differences are merely due to age.
3. Philodendron cremersii is similar to Philodendron macropodum K. Krause described from Brazil (Roraima: Serra de Mairary at 1,000 m). That species also has a petiole sheath that ends somewhat below the blade, but it has smaller leaves which are more nearly elliptic and dry gray-brown above and reddish brown below. In addition, they are broadly rounded at the base (vs. narrowly rounded to acute for Philodendron cremersii).
4. Philodendron cremersii is easily confused with another incompletely known but apparently new species from French Guiana and Surinam. That species has blades that are typically more ovate, averaging about twice as long as broad (vs. an average of 2.5 times longer than broad in Philodendron cremersii). It also differs in having blades that are matte when fresh (also expressed in larger epidermal cells on the upper surface of the blade), which dry yellowish brown rather than dark brown and lack the oblique cross veins common to Philodendron cremersii.
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Philodendron cremersii
2. Novon 4: 211 (1994) — protologue.
Additional photos from iNaturalist by Guillaume Léotard, anonyme973, Jessica Launay, mdoliveira and Nils Servientis - Bivouac Naturaliste