Subspecies, varieties, forms and cultivars of plants belonging to the Matucana aurantiaca group

Matucana aurantiaca is variable and many populations have been given separate species names which in the complex forms a group comprising Matucana aurantiaca, Matucana ritteri, Matucana formosa, Matucana inertexta, Matucana huagalensis and Matucana weberbaueri.

• Matucana aurantiaca (Vaupel) F.Ritter: (subsp. aurantiaca) has about 16 somewhat spiralled and tuberculate ribs. Spines 20-25. Flowers orange-red. Distribution: Northern Peru.
• Matucana aurantiaca subs. currundayensis (F.Ritter) Mottram: Distribution: Cerro Currunday (Otuzco, Samne and adjacent areas), La Libertad department, Peru.
• Matucana aurantiaca subs. fruticosa (F.Ritter) Mottram
• Matucana aurantiaca subs. hastifera (F.Ritter) Mottram
• Matucana aurantiaca subs. polzii (Diers, Donald & Zecher) Mottram
• Matucana calvescens (Kimnach & Hutchison) Buxb.
• Matucana formosa F.Ritter: has 20-30 weackly tuberculate ribs, Spines dark brown tipped black. Flowers crimson. Distribution: valley of the Maranon, Cajamarca and Amazonas, Peru.
• Matucana huagalensis (Donald & A.B.Lau) Bregman, Meerst., Melis & A.B.Pullen: very similar to Matucana intertexta but darker coloured. Flowers white or pale pink. Distribution: Maranon
  and Rio Crisnejas, Cajamarca, Peru.
• Matucana intertexta F.Ritter: has 15-25 crenate ribs, Spines dark brown tipped black. Flowers golden yellow with blood red apices. Distribution: Cajamarca, Peru.
• Matucana pallarensis F.Ritter: Distribution: El Chagual, La Libertad department, Peru.
• Matucana ritteri Buining: has fewer spines (8-15) and 12-22 ribs. Flowers, oblique, relatively narrow-tubed, vermilion-carmine with violet petals edge. Distribution: Otuzco, Department of La Libertad, Peru
• Matucana weberbaueri (Vaupel) Backeb.: has more numerous (25-40) golden yellow or brownish spines and yellow or arange flowers. Distribution: Balsas to Chachapoyas, west side of the Rio Maranon in the department of Amazonas in Peru.
• Matucana weberbaueri var. flammea (Donald) Slaba: has orange-red flowers instead of yellow. Distribution: Balsas above the Canyon Maronan in the province of Chachapoyas, department of Amazonas in Peru.