Urceolina × grandiflora explained

Urceolina × grandiflora, formerly known as Eucharis × grandiflora, is a natural hybrid putatively between U. moorei and U. sanderi of the family Amaryllidaceae, native to western Colombia and western Ecuador.^[1]

The aneutriploid species U. amazonica is often misidentified as U. × grandiflora. Both of them are sterile plants with large fragrant white flowers, but they differ in leaf length, free filament shape, and staminal cup length:^[2]

• U. × grandiflora has shorter leaf blades (20–33 cm × (10–)13–16 cm), linear or narrowly subulate free filaments (1–1.5 mm wide at the base), and staminal cups (5–7 mm long to the apex of teeth) shorter than free filaments (7–8.5(–10) mm long).
• U. amazonica has longer leaf blades ((20–)30–40(–50) cm × (10–)12–18 cm), subulate free filaments (2.8–3.4 mm wide at the base), and staminal cups (11.2–13.8 mm long to the apex of teeth) longer than free filaments (6.5–8(–10) mm long).

Notes and References

1. Web site: Urceolina × grandiflora (Planch. & Linden) Traub. 2023-06-28. Plants of the World Online. Kew Science.
2. Meerow . Alan W. . 1989 . Systematics of the Amazon lilies, Eucharis and Caliphruria (Amaryllidaceae) . Annals of the Missouri Botanical Garden . 76 . 1 . 136–220 . 10.2307/2399347 . 2399347 . 0026-6493.