Translating Echinopsis to English means, like a hedgehog. In wild, they come from central to southern South America, but are easy to grow from seeds in your own home. The cacti regularly re-produce and as offsets they are easily grown. During the flowering stage, a trumpet-shape grows and the flowers are subsequently shown at the top of it.
Echinopsis chamaecereus is known as Peanut cactus with the stems hanging over the edge of a pot. Sadly the cactus I have, in the early 90s, was stolen from outside my flat, however the picture shown is E. chamaecereus lutea. It was grafted onto a rootstock and its colour comes from it not having chlorophyll and therefore not green.
This Echinopsis eyriesii was named after Alexandre Eyries of Le Havre, France. In the wild it is found between Argentina and Brazil and as for temperature, no lower than 10° Centigrade (50° Fahrenheit). Some of these cacti do not always cluster, but as you can see mine has. I have not seen any flowers, yet but I gather those would be white petals.
Adromischus ~ Astrophytum ~ Cephalocereus ~ Cereus ~ Cyanotis ~ Epiphyllum ~ Espostoa ~ Ferocactus ~ Frithia ~ Gymnocalycium ~ Haworthia ~ Hildewintera ~ Lithops ~ Lophocereus ~ Mammillaria ~ Notocactus ~ Opuntia ~ Pilosocereus ~ Rebutia ~ Schlumbergera ~ Sedum ~ Sempervivum ~ Stenocereus ~ Sulcorebutia ~ Tephrocactus ~ Turbinicarpus ~ Weberbauerocereus