''Echinopsis mamillosa'' is a species of

cactus A cactus (, or less commonly, cactus) is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word ''cactus'' derives, through Latin, from the Ancient Greek ...

from

Bolivia , image_flag = Bandera de Bolivia (Estado).svg , flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center , flag_alt2 = 7 × 7 square p ...

., p. 273

Description

''Echinopsis mamillosa'' has a solitary growth habit, with globe-shaped stems up to tall. The stems are dark green, with a diameter of up across, and have 13–17 deep ribs, formed into tubercles. The rounded

areole In botany, areoles are small light- to dark-colored bumps on cacti out of which grow clusters of spines. Areoles are important diagnostic features of cacti, and identify them as a family distinct from other succulent plants. Gordon Rowley - W ...

s are spaced up to and produce yellowish spines with brown tips, the one to four central spines being up to long and the 8–12 radial spines long. The flowers are white with rose tips. They are large in relation to the diameter of the stems, up to across and long. Two subspecies are recognized. Subspecies ''mamillosa'' is shorter (typically only up to tall) with 17 ribs. Subspecies ''silvatica'' is taller and has fewer ribs.

Taxonomy

''Echinopsis mamillosa'' was first described in 1907 by the German botanist Max Gürke. ''E. silvatica''

F.Ritter Friedrich Ritter (9 May 1898 – 9 April 1989) was a German Botany, botanist who collected and described many species of cacti. ''Ritterocereus'' is named in his honour. References

1898 births 1989 deaths {{botanist-stub ...

was included in ''E. mamillosa'' as the subspecies ''silvatica'' by Pierre Braun and E. Esteves Pereira in 1995. The

circumscription Circumscription may refer to: *Circumscribed circle *Circumscription (logic) *Circumscription (taxonomy) * Circumscription theory, a theory about the origins of the political state in the history of human evolution proposed by the American anthrop ...

of ''Echinopsis'' remains controversial; the genus is accepted not to be

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

References

{{Taxonbar, from=Q146014 Cacti of South America Flora of Bolivia mamillosa Plants described in 1907