Sedum

STENOPETALUM Pursh, 1814

Synonyms :

Amerosedum stenopetalum  (Pursh) A.Löve & D.Löve (1985)

Sedum coerulescens  Haworth (1825)

Sedum subclavatum  Haworth (1825)

 

Distribution : W USA

 

 

Description (by 't Hart & Bleij in IHSP, 2003) :

 

Glabrous perennial herbs with decumbent branched stems terminating in rosettes; vegetatively reproducing by means of rosulate offsets on the flowering branches and inflorescences.

 

Leaves alternate, lanceolate-linear with broad scarious bases or oblong-elliptic with narrower bases, sometimes with papillose margins, subterete, 4.3 - 13.8 x 1.4 - 2.7 mm, green, flowering branches erect, branched, 10 - 43 cm.

 

Inflorescences : Cymes mostly with 3 branches, bracts smaller than the leaves, linear-lanceolate, acute and spurred.

 

Flowers 5-merous, sessile or subsessile, sepals broadly sessile, lanceolate or ovate, acute or long-acuminate, pale green or yellow-green, 2 - 3.7 x 0.9 - 1.7 mm, erect, petals (3-) 5 (-8), free, lanceolate or elliptic, obtuse, acute or sometimes with an aristate appendage, yellow with green dorsal keel to almost white, 5.4 - 8 mm, filaments yellow, anthers yellow.

 

Cytology : 2n = 50 - 54, 58, 59?, 62 - 70, 63 – 64

 

Ray Stephenson : Sedum, Cultivated Stonecrops, 1994, p. 210 :

"Not uncommon in gardens, this bright little stonecrop is upright or creeping with narrow, spirally arranged leaves. Viviparous rosettes form on inflorescences and fall to the ground to propagate new plants as each inflorescence disintegrates. Sedum stenopetalum, which has been confused with S. lanceolatum in literature, has bright, shiny, green leaves tinged red, without sharp points. ....  The viviparous nature of this plant is unique to Sedum in this part of the world. Fresh leaves are semiterete, flattened on upper surfaces. Dead leaves are persistent on stems and also envelope adventitious rosettes, protecting them as they blow around before resting in a favorable spot.  ..... Two contrasting clones are in general cultivation. One, ususally labelled "Sedum douglasii", is a more creeping form that vegetatively is very similar to the orthocarpic European Sedum [Petrosedum] montanum. This form does not produce large numbers of adventitious buds nor does it disintegrate completely in autumn. A second form is taller, and often, as a result of lush green growth in spring, takes on the outline of a miniature Christmas tree. In autumn, this plant disintegrates and only scattered, adventitious propagations remain. Clausen found intermediate forms in the wild ....... Sedum stenopetalum is an interesting species that in some forms is not very floriferous, but bright red leaves are attractive in summer."

Two subspecies :

 

Sedum stenopetalum ssp. monantum  (Suksdorf) R.T.Clausen, 1975

 

Sedum stenopetalum ssp. stenopetalum

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