4. Bryophyllum gastonis-bonnieri (Raymond-Hamet & H. Perrier) Lauzac-Marchal, Compt. Rend. Hebd. Séances Acad. Sci. (Ser. D). 278: 2508. 1974.
Kalanchoe gastonis-bonnieri Raymond-Hamet & H. Perrier, Ann. Sci. Nat., Bot., sér. 9, 16: 364. 1912
Herbs, monocarpic, white-mealy, glaucous or not. Stems mostly simple, round, to 7 dm × 1.5 cm. Leaves subrosulate, crowded near base, simple; petiole indefinite, broad, with clasping base; blade green or gray-green, sometimes with maroon or dark green blotches, lanceolate, 15-50 × 5-10 cm, margins sinuate to coarsely crenate, apex acute, surfaces mealy, glaucous or not; bulbils borne in notches of leaf margins, rooting while still attached. Cymes open, corymbiform, 2 dm diam.; branches to 8 cm. Pedicels 5-15 mm. Flowers: calyx pale green, inflated, 18-25 mm, tube 13-15 mm, lobes deltate, contracted basally, 5-10 mm, shorter than tube, apex acute; corolla yellow-green marked with violet-red, 40-50 mm, contracted basally, (sparsely glandular-puberulent), lobes triangular-ovate, 8-11 mm, apex acuminate. 2n = 34.
Flowering winter. Disturbed areas; 0 m; introduced; Fla.; Indian Ocean Islands (Madagascar).
Apparently, Bryophyllum gastonis-bonnieri is or was established only locally in Florida, on Sanibel Island.