TAXONOMY & SYSTEMATICS

Yucca - Suggested plants for outdoor cultivation in low winter temperature zones.

Indehiscent-fruited species.

Yucca aloifolia*
Yucca aloifolia form serratifolia*
Yucca baccata
Yucca baccata ssp. thornberi*
Yucca baccata ssp. vespertina
Yucca brevifolia* (from higher regions)
Yucca carnerosana* (from higher regions)
Yucca decipiens *
Yucca elephantipes* (Mexico-from higher regions)
Yucca faxoniana*
Yucca filifera *(from higher regions)
Yucca gloriosa and cultivars robusta, variegata, medio-picta, marginata
Yucca grandiflora *
Yucca jaliscensis *
Yucca lineriafolia *
Yucca madrensis *
Yucca periculosa *
Yucca recurvifolia and cultivated forms Dolomiten and Schwarzwald, Grubenlampe and Lothringen, Rheintal, Vittorio Emanuele
Yucca schidigera* (from higher regions)
Yucca torreyi * (from higher regions)
Yucca treculiana *
Yucca schottii * (from higher regions)

Dehiscent-fruited species.

Yucca arkansana
Yucca arkansana ssp. louisianensis
Yucca arkansana ssp. freemanii
Yucca angustissima
Yucca angustissima ssp. kanabensis
Yucca angustissima ssp. toftiae
Yucca angustissima ssp. avia
Yucca baileyi
Yucca baileyi form bella (New Mexico)
Yucca baileyi ssp. intermedia
Yucca campestris *
Yucca coahuilensis *
Yucca constricta *
Yucca elata
Yucca elata ssp. utahensis
Yucca elata ssp. verdiensis
Yucca filamentosa
Yucca filamentosa ssp. concava
Yucca filamentosa ssp. smalliana
Yucca flaccida and cultivated forms Golden Sword, Garland Gold, Bright Edge, Bayerwald, Bergkristall, Diamant, Nürnberg
Yucca glauca and forms South Dakota, Nord Dakota, Montana, Nebraska
Yucca glauca ssp. albertana
Yucca glauca ssp. stricta
Yucca harrimaniae
Yucca harrimaniae ssp. gilbertiana
Yucca harrimaniae ssp. neomexicana
Yucca harrimaniae ssp. sterilis
Yucca karlsruhensis (Yucca x Yucca glauca)
Yucca nana
Yucca pallida
Yucca reverchoni *
Yucca rigida *
Yucca rupicola *
Yucca rostrata *
Yucca thompsoniana *
Yucca whipplei *
Yucca whipplei ssp. eremica* (northern California where it is fairly well protected by oak trees).
Other forms: Yucca chilensis, Yucca cochabamba, Yucca danica, Yucca flexilis.
* = Guarding against moisture during the winter months.

Climate data

USA, Great Basin Desert, Hamlyn Valley, Utah, 1,800 m altitude

Temperatures:

July - August: 32°C to 36°C
December - January: -18°C to -25°C
Extreme: 39°C and -29°C

Precipitation: 300 mm p. a. ; mostly in Spring and early Summer.

Central Europe, central Germany, Mannheim, sea level

Temperatures:

July - August: 28°C to 34°C
December - January: -8°C to -14°C
Extreme: 41.5 °C (in 2003) and -18°C

Precipitation: 650 mm p. a. ; January - December irregularly