PHILODENDRON ACREANUM
PROTOLOGUE: Philodendron acreanum , published in Das Pflanzenreich IV. 23Db(Heft 60): 22 (1913). The protologue is reproduced below.
DISTRIBUTION: Ecuador to Brazil (Acre) and N. Bolivia: Bolivia, Brazil North, Ecuador, Peru.
SPECIES DESCRIPTION:
Translated from protologue: Stem terete, climbing, moderately stout, the upper internodes 2–3 cm long and about 8 mm thick. Petiole of the leaves 1.2–2.4 dm long, channelled above, bearing a subcoriaceous persistent sheath that ends 1.5–5 cm below the base of the lamina, 6–8 mm wide on each side below, narrowed upward and rounded at the very apex; lamina thinly leathery, oblong to lanceolate-oblong, obliquely cuspidate-acuminate at the apex and subacute at the base, traversed by very numerous, very densely set, nearly equal lateral veins.
INFLORESCENCE:
Translated from protologue: Peduncles short, 4–6 cm long. Spathe white or yellowish; its tube ovoid, 3–4 cm long and 2–2.3 cm across when rolled up; the blade oblong, 5–7 cm long and 1.2–1.5 cm across, drawn out into a slender, sharp, rather long point. Spadix shortly stipitate; the female zone cylindric, 2.5–3 cm long and nearly 1 cm thick; the male zone subdigitiform, 4–6 cm long, as thick as the female below, tapering upward and obtuse at the very apex. Pistils prismatic, crowned by a broad rounded stigma, 4–6-locular, the locules many-ovuled. Male flowers mostly 3–4-androus.
ECOLOGY:
Found in the Amazonian rainforest (the Hylaea) along the Rio Acre in the western Amazon; recorded in flower in September and January.
ETYMOLOGY:
The epithet acreanum, “of Acre,” refers to the Rio Acre in the western Amazon, along which both original collections were made — near São Francisco and near Cobija. The original description does not explain the name, but it plainly commemorates this river and the surrounding Acre region where the species was gathered.
NOTES:
1. Localities of the original collections: the Brazilian Amazon (the Hylaea) along the Rio Acre. Krause based the species on two Ule collections, both held at Berlin (B): near São Francisco on the Rio Acre (Ule 9213, in flower September 1911) and near Cobija on the Rio Acre (Ule 9238, in flower January 1912).
2. In habit this species is very closely allied to Philodendron cruentum Poepp. of the same section, but is distinguished by the structure of the ovaries and by the colour of the spathe.
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Philodendron acreanum
2. Das Pflanzenreich IV.23Db (Heft 60): 22 (1913) — protologue.
3. iNaturalist: Philodendron acreanum
Additional photos from iNaturalist by Jared Shorma, Dr. Alexey Yakovlev, Nate Hartley and katastrophe1