Thelocactus  (Thelocactus hastifer)

Classified as Vulnerable (VU) on the IUCN Red List (1) and listed on Appendix II of CITES (3).

Thelocactus hastifer can be immediately recognised by its elongated stem, which may be erect or lie along the ground (‘decumbent’). This elongate stem is a unique character among the species of this genus, and even young seedlings can be easily distinguished from other Thelocactus species by the elongate rather than rounded growth. Individual plants have a swollen root and a thin stem, about 5.5 centimetres in diameter, which is divided into 13 to 18 ribs. In older individuals, the stem branches from the base. The main body of the plant has a very thin collar between the root and the upper part of the stem, which is unable to bear the weight of the stem, so that it eventually grows lying on the ground. The spines of this cactus are straight and needle-like, and consist of 20 to 25 ‘radial’ spines, which are white in colour and measure up to 1.5 centimetres long, and 4 to 5 ‘central’ spines, which are longer, at up to 2.6 centimetres, and whitish to black in colour (4).

Found only in few localities in the municipality of Cadereyta de Montes, Querétaro, Mexico (5).

This species grows on limestone hills at altitudes of 1,800 to 2,050 metres above sea level, where it is associated with desert scrub habitat (5).

Thelocactus hastifer flowers from February to May, producing magenta flowers that measure 3.5 to 7.5 centimetres wide. The flowers open from midday to early afternoon and last one or two days (4) (5). The fruits, which are relatively small for the genus, mature from March to July, and the shiny black seeds are released from an opening at the base of the fruit. The reproductive rate of this cactus is considered to be low, as only 30 seeds are produced on average per plant per year (5).

Human activities are the main factors affecting the populations of this cactus. Land conversion for agricultural purposes, grazing, and expansion of populated areas are reducing its habitat, while illegal collection can also affect population size (5).

Thelocactus hastifer is listed on Appendix II of the Convention on International Trade in Endangered Species (CITES), which permits trade of wild plants in a controlled way to avoid utilization incompatible with their survival (3). Within Mexico, the species is also subject to special protection (Pr) on the Norma Oficial Mexicana NOM-059 (6). The area where Thelocactus hastifer grows is rich in rare and threatened cacti, and setting it aside as a natural reserve should be considered (2).

To find out more about Thelocactus species see:

• The Genus Thelocactus:
  http://www.thelocactus.cactus-mall.com/
• Sánchez, E.A.S., Hernández Martínez, M.M. and Chávez, R. (2006) Ficha técnica de Thelocactus hastifer. In: Sánchez, E. (Ed.) Apuntes Técnicos para el Conocimiento de la Situación de Conservación de Especies de la Familia Cactaceae en el estado de Querétaro. Jardín Botánico Regional de Cadereyta “Ing. Manual González de Cosío”, Querétaro, Mexico. Available at:
  http://www.conabio.gob.mx/conocimiento/ise/fichasnom/Thelocactushastifer00.pdf