Echinopsis densispina, is a species of Echinopsis found in Argentina.[1]
Echinopsis densispina grows solitary. The egg-shaped, grey-green to dark green shoots reach heights of growth of up to with a diameter of 5.5 centimetres with around 17 notched ribs divided into tubercles. The yellowish-white areoles located on them are sometimes sunken and are up to apart. The four to seven central spines are light to dark brown with darker tips. The central spines are straight to slightly curved and thickened at their base and long or much shorter and inconspicuous. The radial spines are 16 to 22 whitish, bristle-like, flexible and long. The short and broad, funnel-shaped, yellow to orange flowers are up to long[2]
Echinopsis densispina is widespread in the Jujuy province of Argentina at altitudes of 1500 to 3000 meters.
The first description by Erich Werdermann was published in 1934.[3] The specific epithet densispina is derived from the Latin words densus for 'dense' and -spinus for 'thorny'. Nomenclature synonyms are Lobivia densispina Werderm. ex Backeb. & F.M.Knuth (1936), Hymenorebutia densispina (Werderm.) Buining (1939), Salpingolobivia densispina (Werderm.) Y.Itô (1957), Lobivia famatimensis var. densispina (Werderm.) Backeb. (1960), Lobivia haematantha subsp. densispina (Backeb. & F.M.Knuth) Rausch (1975), Lobivia haematantha var. densispina (Backeb. & F.M.Knuth) Rausch (1975) and Lobivia haematantha subsp. densispina (Backeb. & F.M.Knuth) Rausch ex G.D.Rowley (1982).