Saturday 18 May
Cactus (Ariocarpus trigonus)

Cactus fact file
- Description
- Biology
- Range
- Habitat
- Status
- Threats
- Conservation
- Find out more
- Glossary
- References
- Print factsheet
Cactus description
| Kingdom | Plantae |
| Phylum | Tracheophyta |
| Class | Magnoliopsida |
| Order | Caryophyllales |
| Family | Cactaceae |
| Genus | Ariocarpus (1) |
This striking cactus (Ariocarpus trigonus) is only visible from its claw-like tubercles that emerge through the soil; the majority of the stem remains hidden underground (2). Unusually amongst cacti, the yellow-green plant is spineless, lacking areoles on the smooth upper surface of the tubercles (2). Lemon-yellow flowers emerge in a ring on the crown of the stem and when fertilised these develop into small white berries (4).
- Size
- Diameter: up to 30 cm (2)
Cactus biology
This cactus flowers between September and December, fruits develop in the spring and the rains (which begin in May) help to disperse the seeds by washing them from the centre of the plant (2).
TopCactus range
Ariocarpus trigonus is found over a fairly wide geographical range in northeastern Mexico, from the eastern edge of the mountains of the Sierra Madre Oriental, and concentrated in the Valley of Jaumave in the state of Tamaulipas (2).
TopCactus habitat
Ariocarpus trigonus inhabits dry thorn forest and scrubland amongst very rocky soil, or limestone gravel. It is found on low hills, at altitudes between 200 and 800 metres above sea level (2).
TopCactus status
This cactus is classified as Least Concern (LC) on the IUCN Red List (1), and listed on Appendix I of CITES (3).
TopCactus threats
Members of the genus Ariocarpus are known as 'living rock' or 'fossil cacti' due to their unusual appearance (4), and they have been widely in demand from collectors for this reason (2). The demand for this species for the commercial cactus trade is a significant threat to its survival together with the development of the land for agriculture. Large areas of land have been converted for citrus plants or irrigated for cereal crops, and non-developed areas are often occupied by goats, which graze and trample on this species (2).
TopCactus conservation
Ariocarpus trigonus is listed on Appendix I of the Convention on International Trade in Endangered Species (CITES), which bans international trade in this unusual cactus based on wild plants (3). The Valley of Jaumave is home to many unusual and rare species of plants and animals and it has been suggested as an excellent candidate for a nature reserve (2).
TopAuthentication
Authenticated (20/3/03) by Dr Nigel Taylor, Royal Botanic Gardens, Kew.
http://www.rbgkew.org.uk
Glossary
- Areoles
- In cacti, the felted or woolly, cushion-like structures from which spines grow, flowers develop and new stems arise.
- Tubercules
- In cacti, a small wart-like or angular swelling upon the stem.
References
-
IUCN Red List (March, 2011)
http://www.redlist.org - Anderson, E.F., Arias Montes, S. & Taylor, N.P. (1994) Threatened Cacti of Mexico. Royal Botanic Gardens, Kew.
-
CITES (February, 2003)
http://www.cites.org - Hewitt, T. (1993) The Complete Book of Cacti and Succulents. Dorling Kindersley, London.
More »Related species
Close
Image credit
© Nigel P. Taylor / Royal Botanic Gardens, Kew
Royal Botanic Gardens, Kew
Richmond
Surrey
TW9 3AB
United Kingdom
Tel: +44 (0) 208 332 5000
Fax: +44 (0) 208 332 5197
info@kew.org
http://www.rbgkew.org.uk
Close
Link to this photo
Embed this ARKive thumbnail link by copying and pasting the code below.
Terms of Use - The displayed thumbnail may be used as a link from your website to ARKive's online content for private, scientific, conservation or educational purposes only. It may NOT be used within Apps.
Read more about
Close
MyARKive
MyARKive offers the scrapbook feature to signed-up members, allowing you to organize your favourite ARKive images and videos and share them with friends.
Close
Terms and Conditions of Use of Materials
Copyright in this website and materials contained on this website (Material) belongs to Wildscreen or its licensors.
Visitors to this website (End Users) are entitled to:
- view the contents of, and Material on, the website;
- download and retain copies of the Material on their personal systems in digital form in low resolution for their own personal use;
- teachers, lecturers and students may incorporate the Material in their educational material (including, but not limited to, their lesson plans, presentations, worksheets and projects) in hard copy and digital format for use within a registered educational establishment, provided that the integrity of the Material is maintained and that copyright ownership and authorship is appropriately acknowledged by the End User.
End Users shall not copy or otherwise extract, alter or manipulate Material other than as permitted in these Terms and Conditions of Use of Materials.
Additional use of flagged material
Green flagged material 
Certain Material on this website (Licence 4 Material) displays a green flag next to the Material and is available for not-for-profit conservation or educational use. This material may be used by End Users, who are individuals or organisations that are in our opinion not-for-profit, for their not-for-profit conservation or not-for-profit educational purposes. Low resolution, watermarked images may be copied from this website by such End Users for such purposes. If you require high resolution or non-watermarked versions of the Material, please contact Wildscreen with details of your proposed use.
Creative commons material
Certain Material on this website has been licensed to Wildscreen under a Creative Commons Licence. These images are clearly marked with the Creative Commons buttons and may be used by End Users only in the way allowed by the specific Creative Commons Licence under which they have been submitted. Please see http://creativecommons.org for details.
Any other use
Please contact the copyright owners directly (copyright and contact details are shown for each media item) to negotiate terms and conditions for any use of Material other than those expressly permitted above. Please note that many of the contributors to ARKive are commercial operators and may request a fee for such use.
Save as permitted above, no person or organisation is permitted to incorporate any copyright material from this website into any other work or publication in any format (this includes but is not limited to: websites, Apps, CDs, DVDs, intranets, extranets, signage, digital communications or on printed materials for external or other distribution). Use of the Material for promotional, administrative or for-profit purposes is not permitted.












