EDIT: All the articles for Warzenkaktus in the OP should be der Warzenkaktus. LEO won't let me edit any but the first one. It also tells me that none of what follows is formatted correctly for LEO when I try to edit it. So here it is all again. "Der Text konnte nicht formatiert werden. Daher werden z.B. Links nur als reiner Text dargestellt."

http://wordnetweb.princeton.edu/perl/webwn?s=...
• S: (n) mammillaria (any cactus of the genus Mammillaria)

http://www.merriam-webster.com/dictionary/mam...
mammillaria noun \"\
Full Definition of MAMMILLARIA
[…]
2 : any cactus of the genus Mammillaria
Origin of MAMMILLARIA
New Latin, from Latin mammilla + New Latin -aria
NOTE from Merriam-Webster: This word doesn't usually appear in our free dictionary, but the definition from our premium Unabridged Dictionary is offered here on a limited basis.

http://dictionary.reference.com/browse/mammillaria
mam•mil•lar•i•a [mam-uh-lair-ee-uh]
noun
any of various cacti of the genus Mammillaria, including the pincushion cactus.
Origin:
< Neo-Latin (1824); see mammilla, -aria
Dictionary.com Unabridged
Based on the Random House Dictionary

http://plants.usda.gov/core/profile?symbol=MAMMI
Mammillaria Haw.
Globe cactus

http://www.efloras.org/florataxon.aspx?flora_...
4. Mammillaria Haworth, Syn. Pl. Succ. 177. 1812.
[name conserved]
Pincushion, globe cactus, chilita [Latin mamilla, nipple, in reference to shape of tubercles, which produce “milky” white latex in some species]

http://itis.gbif.net/pls/itisca/next?v_tsn=19...
Scientific Name: Mammillaria Haw.
[…]
Vernacular name(s): fishhook cactus [English]
globe cactus [English]
pincushion cactus [English]

http://en.wikipedia.org/wiki/Mammillaria
The genus Mammillaria is one of the largest in the cactus family (Cactaceae), with currently 171 known species and varieties recognized.
[…]
Numerous species are commonly known as nipple cactus, fishhook cactus or pincushion […].

http://www.uaex.edu/yard-garden/resource-libr...
Nipple Cactus
Latin: Mammillaria sp.

http://aristonorganic.com/2013/07/19/mammilla...
Mammillaria – the Nipple cactus

http://en.wikipedia.org/wiki/Fishhook_cactus
Fishhook cactus is a common name for any hook-spined species of the genera Mammillaria or Sclerocactus.

http://www.rugusavay.com/pincushion-cactus-fl...
Pincushion Cactus (Mammillaria)

http://pss.uvm.edu/pss123/cacmam.html
Mammillaria
[…]
Common name: Pincushion Cactus

**********

http://www.biologie.uni-ulm.de/cgi-bin/query_...
Mammillaria Haw.
[…]
Warzenkaktus

http://blumen.esotericplus.com/14-54-12.htm
Mammillaria • Warzenkaktus

http://www.gartenheinz.de/pflanzen/kakteen/ma...
Warzenkaktus (Mammillaria): Pflege und Standort

A genus of about 170 species of cacti. Native to the southwestern US, Mexico, West Indies, & Central America.
Pictures / Bilder of various species of Mammillaria

Other English names (not proposed):
strawberry cactus

Andere deutsche Namen (nicht vorgeschlagen):
die Brustwarzendistel

Taxonomic citation:
Mammillaria Haworth, Synopsis Plantarum Succulentarum 177. 1812.

3167

Die Mammilarien-Ausstellung zieht besonders viele Kakteenliebhaber an.
http://www.linz.at/images/Newsletter_Botanisc...

Arbeitskreis für Mammillarienfreunde e.V.
http://www.mammillaria.eu/

Beim Hochklettern standen wir dann zu unserer Freude, aber völlig überraschend, den kleinen, in Felsspalten wachsenden Mammillarien gegenüber. Weitere Besuche folgten 2009 und 2011. Der Zustand der kleinen Warzenkakteen war vor allem zu den beiden letzten Terminen sehr unterschiedlich ...
http://www.mammillaria.eu/Probeartikel/Probea...

Mammillaria, Mamillaria, die
Von Duden empfohlene Schreibung:
Mammillaria 
Warzenkaktus (mexikanische Kakteengattung)
Plural: die Mammillarien
http://www.duden.de/rechtschreibung/Mammillaria

Google:
"eine Mammillaria" --- Aproximadamente 5.110 resultados
"ein Warzenkaktus" --- Aproximadamente 105 resultados
Warzenkaktus site:mammillaria.eu --- 0

Additional proposal.