PHILODENDRON ALTERNANS
PROTOLOGUE: Philodendron alternans , published in Synopsis Aroidearum Complectens Enumerationem Systematicam Generum et Specierum Huju Ordinis 75 (1856).
Philodendron alternans Schott, Syn. Aroid.: 75 (1856).
Petiolus tenuis brevis; lamina lanceolata, utrinque sensim angustata, costa e petiolo attenuata, venulis inconspicuis.
Flor. Flum. Tab. 116.
SYNONYMS:
HOMOTYPIC SYNONYMS: Arum alternum Vell.
DISTRIBUTION: Brazil (Rio de Janeiro): Brazil Southeast.
SPECIES DESCRIPTION:
Translated from protologue: Petiole slender, short; blade lanceolate, gradually narrowing on both sides, the midrib tapering from the petiole, the veins inconspicuous.
ETYMOLOGY:
Although the original description does not explicitly explain the name, it likely refers to the Latin alternans, "alternating." The protologue does not say what alternates: Schott's diagnosis for this species states only that the veins are inconspicuous, with no description of their arrangement, in contrast to the closely allied Philodendron lanceolatum, whose veins are described as spreading. The epithet may instead allude to the plant's alternate leaf arrangement, which the protologue also does not address.
NOTES:
1. Philodendron alternans was placed immediately after Philodendron lanceolatum in Schott's synopsis, and the opening of its diagnosis (petiole, blade shape, midrib) repeats lanceolatum's almost word for word. The two entries diverge at the leaf venation, described as inconspicuous in Philodendron alternans and as spreading in Philodendron lanceolatum; Schott's entry for alternans does not repeat lanceolatum's further remarks on the peduncle-to-spathe ratio or anther coordination, which are simply not addressed here.
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Philodendron alternans
2. Synopsis Aroidearum Complectens Enumerationem Systematicam Generum et Specierum Hujus Ordinis: 75 (1856) — protologue.
3. iNaturalist: Philodendron alternans
Additional photos from iNaturalist by henrycc and David Jeffrey Ringer