Relationships between Number of Stem Segments on Longest Stems, Retention of Terminal Stem Segments and Establishment of Detached Terminal Stem Segments for 25 Species of Cylindropuntia and Opuntia (Cactaceae)

Recruiting mechanisms of Cylindropuntia leptocaulis (Cactaceae) in the Southern Chihuahuan Desert

“…leptocaulis DC. (Cactaceae), which measures from 0.5 to 1.5 m in height, has a woody, well-defined trunk with cylindrical branches that form from the vertical juxtaposition of terminal joints (Bobich and Nobel, 2001) or stem segments (Evans et al, 2004). The terminal stem segments detach easily from the plant when touched, as the joints between them are extremely fragile.…”

“…Ramet establishment is a frequent event in Opuntia and Cylindropuntia, but between species and between genera, variability has been reported (Allen et al, 1991;Bobich and Nobel, 2001;Ebert, 2006;Evans et al, 2004;Mandujano et al, 1998Mandujano et al, , 2007. Evans et al (2004) analyzed the establishment of stem segmentsdalso known as terminal joints, in the terminology of Bobich and Nobel (2001)din ten Cylindropuntia species and in the pads of 15 Opuntia species in the southwestern United States; the terminal joints of the former were shown to have a lower rooting percentage than Opuntia pads (32 vs. 71%, respectively).…”

“…Only a handful of observational studies have been published, and with contradictory results: Yeaton (1978) and Cody (1993) report an association between nurse plants and juveniles produced by sexual reproduction, while Reyes-Olivas et al (2002) observe no such association. Other observational studies on four species (Bobich and Nobel, 2001) and experimental studies on 10 species (Evans et al, 2004) of Cylindropuntia from the Sonoran Desert showed that all are able to propagate clonally, but no analysis was performed of the environmental conditions under which this type of plant recruitment takes place.…”

“…Evans et al (2004) analyzed the establishment of stem segmentsdalso known as terminal joints, in the terminology of Bobich and Nobel (2001)din ten Cylindropuntia species and in the pads of 15 Opuntia species in the southwestern United States; the terminal joints of the former were shown to have a lower rooting percentage than Opuntia pads (32 vs. 71%, respectively). Apparently, the greater volume of Opuntia cladodes permits a higher degree of water and carbohydrate storage, making survival during dry periods possible (Bobich and Nobel, 2001).…”

Mixed reproduction systems in Opuntia monacantha (Cactaceae) in Southern Brazil

“…the fragmentation of the cladodes as well as fruitfall near the mother plant are common but efficient mechanisms for clonal multiplication in Opuntia (nerd & Mizrahi 1997, Mandujano et al 1998a. there is an increase in autogamy generated by the growth clones in these cases, favoring the appearance of homozygotic individuals as well as influencing the dynamics of population establishment and permanence (Mandujano et al 1998b, Evans et al 2004, Griffith 2004. The association between sexual and asexual reproduction (clonal multiplication) can reduce the long-term effects of endogamy and favor genetic diversity and the installation, generation, permanence, and distribution of natural populations of different cactus species -as has been demonstrated for Opuntia rastrera f.c.a.Weber.…”