Dudleya

RUBENS (Brandegee) Britton & Rose, 1903

Synonyms :

 

Cotyledon rubens  Brandegee (1889) / Echeveria rubens  (Brandegee) A.Berger (1930)

 

Subgenus Dudleya

 

Distribution : Mexico (southern Baja California: Sierra San Francisco to Sierra La Giganta); mostly northern-exposed volcanic cliffs, 500 - 1200 m.

 

 

Description (according to IHSP, 2003) :

 

Stems 5 - 15 (-30) x 1 - 2.5 cm.

 

Rosette 6 - 11 cm in diameter, with 10 - 20 leaves, solitary or few (rarely up to 25) together).

 

Leaves oblong to oblong-lanceolate, rarely obovate, acute to delicately pointed or rarely long-attenuate, 3 - 7 x 1 - 2 cm, farinose.



Inflorescence : Scapes ascending to erect, 7 - 20 cm, reddish, inflorescence reddish, with 2 - 3 ascending not or 1x branched scorpioid branches, these 2 - 12 cm, with 2 - 12 flowers, pedicels ascending to erect, lowermost pedicels 4 - 10 mm.

 

Flowers : Calyx 4 - 8 mm, sepals triangular to lanceolate, acute to long-attenuate, 3 - 6 x 2 - 4 mm, corolla 4.5 - 7 (basally) to 4 – 7 (apically) mm in diameter, petals oblong, erect, partly apically somewhat spreading, 8 - 15 x 1.5 – 3 mm, reddish to apricot-coloured, tube 5 - 7 mm.

 

Flowering time : April to May.

 

Cytology : n = 34, 51, 68

 

Apparently the only species of the genus in N Baja California Sur at altitudes above 500 m. It is similar to D. pulverulenta ssp. arizonica but is distinguished by the branching pattern, the smaller number of bracts, shorter inflorescences, shorter pedicels and a higher chromosome number. Differences to the equally similar D. cymosa are the more than 10 cm long stems, shorter pedicels, petals fused for more than 1/3 of their length, and the polyploid chromosome number (Nakai 1988b).

 


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