13. Kalanchoe × houghtonii Ward (2006: 94) (Fig. 12).

Type:— U.S.A., Florida, central Merritt Island, Brevard County, 10 February 2000, D.B. Ward 10700 [collected with R.B. Huck] (holotype, consisting of three parts, FLAS!; isotypes FTG, NY !, SD, US !, USF).

Iconography:— Smith et al. (2015), Guillot Ortiz et al. (2008), González Gutiérrez et al. (2019: e9), Gallo (2019), Smith (2019), Shtein et al. (2021).

Secondary distribution:— Algeria = Sakhraoui et al. 2024. Portugal = Silva et al. (2015) and Smith et al. (2015). Italy = (Calabria) cited by Spampinato et al. (2022); (Sardinia) cited by Podda et al. (2012) and Puddu et al. (2016) as casual. Note that K. × houghtonii, as a suspected hybrid between K. daigremontiana and K. delagoensis, has been known for Italy since the early 2000s (Del Guacchio 2005: 214–215). France = (Pyrenees) cited by Lewin et al. (2020: 42), as K. daigremontiana, Lewin & Schwab (2021: 25) . (Corsica) = Not recorded (Puddu et al. 2016). Spain (Catalonia) = cited by Saez & Aymerich (2021), (Galicia) González-Martínez (2017: 58), Laguna Lumbreras et al. (2014), and Aymerich & Saez (2019).

[Also in Argentina, Australia, Caribbean (Cuba), China, Macaronesia, New Zealand, Singapore (Malaysia), U.S.A.]

Notes:—The name K. × houghtonii was published for the hybrid between K. daigremontiana and K. delagoensis (Smith 2019) . The epithet ‘ houghtonii ’ was used by Sykes (1992: 9), as “ Bryophyllum “ Houghtonii ””, but this designation was likely intended as a cultivar name (see also Sykes 2004: 20). A combination in Bryophyllum for this nothospecies was later validly published, as B. × houghtonii (D.B.Ward) Forster (2006: 383) .