Origin and Habitat: Notocactus scopaSN|15901]]SN|15901]] var. xiphacanthus is a micro endemic form, found only on a very isolated hill north of Minas Dept. Lavalleja, Uruguay.
Habitat and ecology: The plants grow in crevices on very steep, partially inaccessible rocks. The substrate is acidic (pH 5.3), no other cacti grows at the site.

• Notocactus scopa f. xiphacanthus (W.R.Abraham) N.Gerloff & Neduchal
• Notocactus scopa var. xiphacanthus W.R.Abraham

• Parodia scopa (Spreng.) N.P.Taylor
• Cactus scopa Spreng.
• Cereus scopa (Spreng.) Salm-Dyck ex DC.
• Echinocactus scopa (Spreng.) Link & Otto
• Echinopsis scopa (Spreng.) Carrière
• Malacocarpus scopa (Spreng.) Britton & Rose
• Notocactus scopa (Spreng.) A.Berger
• Peronocactus scopa (Spreng.) Doweld
• Notocactus scopa f. albicans (Arechav.) N.Gerloff & Neduchal
• Echinocactus scopa var. albicans Arechav.
• Echinocactus scopa f. albicans (Arechav.) Schelle
• Notocactus scopa var. albicans (Arechav.) Hofacker
• Notocactus scopa f. albilanatus Jahn
• Notocactus scopa f. candidus (Pfeiff.) Krainz
• Echinocactus scopa var. candidus Pfeiff.
• Echinocactus scopa f. candidus (Pfeiff.) Schelle
• Notocactus scopa var. candidus (Pfeiff.) Backeb.
• Notocactus scopa f. cobrensis (N.Gerloff) N.Gerloff & Neduchal
• Notocactus scopa var. cobrensis N.Gerloff
• Notocactus scopa f. daenikerianus (Krainz) Krainz
• Notocactus scopa var. daenikerianus Krainz
• Notocactus scopa f. erythrinus Havlíček
• Notocactus scopa f. glauserianus (Krainz) Krainz
• Notocactus scopa var. glauserianus Krainz
• Notocactus scopa f. machadoensis (W.R.Abraham) N.Gerloff & Neduchal
• Notocactus scopa var. machadoensis W.R.Abraham
• Notocactus scopa var. murielii Hofacker
• Notocactus scopa f. ramosus (Osten) Backeb.
• Echinocactus scopa f. ramosus Osten
• Notocactus scopa var. ramosus (Osten) Backeb.
• Notocactus scopa f. ruberrimus Frič
• Notocactus scopa f. xicoi (W.R.Abraham) N.Gerloff & Neduchal
• Notocactus scopa var. xicoi W.R.Abraham
• Notocactus scopa f. xiphacanthus (W.R.Abraham) N.Gerloff & Neduchal
• Notocactus scopa var. xiphacanthus W.R.Abraham
• Notocactus soldtianus Vliet
• Parodia scopa f. cristata hort.
• Parodia scopa f. splendens hort.

• Parodia scopa subs. marchesii (W.R.Abraham) Hofacker
• Notocactus scopa subs. marchesii (W.R.Abraham) Doweld
• Notocactus scopa var. marchesii W.R.Abraham
• Notocactus scopa f. marchesii (W.R.Abraham) N.Gerloff & Neduchal
• Peronocactus scopa subs. marchesii (W.R.Abraham) Doweld

• Parodia scopa subs. neobuenekeri (F.Ritter) Hofacker & P.J.Braun
• Notocactus neobuenekeri F.Ritter
• Notocactus scopa subs. neobuenekeri (F.Ritter) Doweld
• Parodia neobuenekeri (F.Ritter) Anceschi & Magli
• Peronocactus scopa subs. neobuenekeri (F.Ritter) Doweld

• Parodia scopa subs. succinea (F.Ritter) Hofacker & P.J.Braun
• Notocactus scopa subs. succineus (F.Ritter) Doweld
• Notocactus scopa f. succineus (F.Ritter) N.Gerloff & Neduchal
• Notocactus succineus F.Ritter
• Parodia succinea (F.Ritter) N.P.Taylor
• Peronocactus scopa subs. succineus (F.Ritter) Doweld
• Parodia scopa subs. succinea f. albiseta hort.
• Notocactus scopa var. albispinus hort.
• Notocactus succineus var. albisetus hort.
• Notocactus succineus var. albispinus hort.
• Parodia scopa f. albiseta hort.
• Parodia scopa var. sulphurea hort.
• Notocactus scopa var. sulphureus hort.
• Notocactus sulphureus hort.

• Parodia scopa cv. inermis
• Notocactus scopa f. monstruosus
• Notocactus scopa cv. inermis
• Parodia scopa f. monstruosa
• Parodia scopa cv. inermis cristata
• Notocactus scopa f. monstruosus cristatus
• Notocactus scopa cv. inermis cristatus hort.
• Parodia scopa f. monstruosa cristata

Description: Notocactus scopaSN|15901]]SN|15901]] fa xiphacanthus is one of the morphological or local forms of Notocactus scopaSN|15901]]SN|15901]] distinguished by larger stems with fewer ribs and usually a long, dark, sword-shaped central spine. Also the flowers are somewhat larger. This variety has a great variability at the site.
Stem: Up to 60 cm long, 11 cm in diameter, epidermis blue-green.
Ribs: 19-23, flat, about 3 mm high, straight to slightly turned.
Radial spines: About 30, white, 4-6 mm long.
Central spines: 1-5, but usually only one, upright, up to 35 mm long, dark brown, occasionally light brown. In habitat at the type site about 30% of the plants have more than one central spine. In these plants, the central spines stand side by side, and are usually lighter in colour, shorter and sometimes indistinguishable from the radials.
Flowers: 40 mm long, 50 mm wide, buds and basal part of the flower covered with grey wool, petals yellow, lanceolate. Self-sterile.
Seeds: In this variety the seeds have bigger testa cells.

Bibliography: Major references and further lectures
1) Abraham, Wolf-Rainer (1987): Succulenta 66 (12): 256 – 260.
2) Gebauer, Alfred “Die Erstbeschreibung des Jahres 1987” in Notocactus (1988)
3) Gerloff & Neduchal “Die Pflanzen um Notocactus scopa,” INTERNOTO 3/4, 2003.

Cultivation and Propagation: It is easy to grow. It prefers a neutral to slightly acidic mineral-based potting mix with a good drainage. It likes a warm bright location, does great in partial shade but doesn't like full, hot blazing sun in the central summer month. Can support quite some water during the growing season but pot plants in winter are wet-sensitive and needs to be kept dry (rots easily if soil is wet and cold) tends to lose its roots in winter. Usually it is recommended to over-winter this plant in a bright and warm greenhouse with at least 8-10° C, but it has proved to tolerate temperatures as low as -5° C for short periods.
Propagation: Seeds, cuttings or root suckers (if available). Not too difficult to raise from seed.