Plant in full sun in a well-drained soil with occasional irrigation. Can handle a light frost but likely damaged in temperatures below 28°F. An interesting and unique plant with the unusual color combination of purple and gray on leaves that appear to be turned on their edge.

This plant comes from south central Madagascar between Betroka and Ihosy. It was first described in 1923 by Jean-Henri Humbert (1887-1967), a French botanist and professor at the University of Algiers who explored Madagascar on numerous occasions and was editor of the journal Flore de Madagascar et des Comores (Flora of Madagascar and the Comoros). The specific epithet is from the Latin words 'crass' meaning "solid", "thick", "fat" or "dense" and the superlative suffix 'sssima' meaning "to the greatest degree" which combines to mean "the thickest" in reference to the thick leaves. Besides Vertical Leaf Senecio, it is also commonly called , Propeller Plant, for the way the leaf edges point up and down rather than being horizontal to the ground and also called Lavender Steps and Purple Line for the colorful leaf margins.

According to Gordon Rowley in his book Succulent Compositae, this plant first made headlines when it was described and figured by Eric Walther in the October 1930 Cactus and Succulent Journal of America (Vol. 2 No. 4). Walther, himself quite well known later as the author of the landmark book Echeveria, was judging the 1930 Cactus and Succulent Society of America's annual show and reporting on it in journal where he noted that an exhibit by Santa Barbara's Park Supervisor E.O. Orpet had Senecio crassissimus in it and he called it "the rarest succulent shown". This plant had been introduced as Senecio sp. B.P.I#77934 only a couple years prior by Charles F. Swingle, who was on a Bureau of Plant Industry (USDA) sponsored trip to Madagascar in 1928, but Walther was confident that it was in fact the Senecio crassissimus that Humbert had described. The following month, in the November 1930 issue of the journal, it was noted that Miss Kate Sessions in San Diego (often called "Mother of Balboa Park.") and a Colonel Kewen in South Pasadena also had this plant from the Bureau of Plant Industry distribution. All of this notoriety and mention of the plant caused Charles F. Swingle to write a letter to the editor of the journal that was published in the February 1931 issue where he wrote that "Dr. Henri Humbert was the leader of the exploration party which resulted in the introduction of this plant. However , I collected this particular material and will take all the blame for not recognizing it as S. crassissimus. I think it safe to accept Mr. Walther's classification, for I find in our files a photograph taken by Dr. Humbert on our trip, showing S. crassissimus in flower. Although Madagascar has many interesting and virtually unknown Senecios, I believe there is no other which has the characteristic type of leaf arrangement that this has." We so often think such plants are new until such information surfaces that indicates they have been around for quite a while. We have grown this plant since being entranced with a planting of it in 2001 at the newly opened Disney California Adventure theme park in Anaheim. 

The information about Senecio crassissimus displayed on this web page is based on our research conducted in the nursery's horticultural library and from reliable online resources. We also include observations made about it as it grows in our nursery gardens and other gardens we have visited, as well how the crops have performed in containers in our nursery field. We will also incorporate comments we receive from others and welcome hearing from anyone with additional information, particularly if they can share cultural information that would aid others in growing this plant.