Cochise Pincushion Cactus (Escobaria robbinsorum)

During 1999, DBG received 33 plants, each approximately 2 cm in diameter, from a private individual. These plants immediately flowered at the time they normally would have, and controlled cross-pollinations were conducted, producing 78 fruits and a total of 2827 seeds.

The failure to germinate seeds collected from any of the plants, provided support to the idea that freezing may not be appropriate for some seeds of desert plants, notably members of Cactaceae. Experimentation with some other species of cactus has provided similar results. The protocol for the storage process for Cactaceae is being re-examined at Desert Botanical Garden (DBG). Another collection was made from the same site during 1995. Five seeds were collected from each of 50 plants. During 1999, DBG received 33 plants, each approximately 2 cm in diameter, from a private individual. These plants immediately flowered at the time they normally would have, and controlled cross-pollinations were conducted, producing 78 fruits and a total of 2827 seeds. The seeds were allowed to dry in the partially dry fruits, and then cleaned and counted by hand. They were stored in an airtight foil pouch after 6 weeks of drying at 63 degrees C. Germination tests have been conducted, resulting in 64% germination. Approximately 30 seedlings remain alive from this experiment. They are approximately 1 mm in diameter at 6 months old, and have developed the first two to three spine clusters.

The first collection was made in 1987 when 812 seeds were collected. The seeds appeared immature at the time of collection, and germination tests failed. The seeds had been immediately frozen following cleaning and counting, prior to establishing a baseline germination percentage. If the seeds were not fully mature, it is possible that freezing killed the developing embryos. The failure to germinate seeds collected from any of the plants, provided support to the idea that freezing may not be appropriate for some seeds of desert plants, notably members of Cactaceae. Experimentation with some other species of cactus has provided similar results. The protocol for the storage process for Cactaceae is being re-examined at Desert Botanical Garden (DBG). Another collection was made from the same site during 1995. Five seeds were collected from each of 50 plants. During 1999, DBG received 33 plants, each approximately 2 cm in diameter, from a private individual. These plants immediately flowered at the time they normally would have, and controlled cross-pollinations were conducted, producing 78 fruits and a total of 2827 seeds. The seeds were allowed to dry in the partially dry fruits, and then cleaned and counted by hand. They were stored in an airtight foil pouch after 6 weeks of drying at 63 degrees C. Germination tests have been conducted, resulting in 64% germination. Approximately 30 seedlings remain alive from this experiment. They are approximately 1 mm in diameter at 6 months old, and have developed the first two to three spine clusters.

Seedbanking for this species calls into question the protocol for establishing a conservation seedbank, as each plant may produce only 1200 seeds during its lifetime. Until germination tests provide more definite results, the Garden maintains a conservative approach to augmenting the seedbank it has established. Desert Botanical Garden has only 2 field seed collections, both obtained from a population occurring on privately owned land. The first collection was made in 1987 when 812 seeds were collected. The seeds appeared immature at the time of collection, and germination tests failed. The seeds had been immediately frozen following cleaning and counting, prior to establishing a baseline germination percentage. If the seeds were not fully mature, it is possible that freezing killed the developing embryos. The protocol for the storage process for Cactaceae is being re-examined at Desert Botanical Garden (DBG). Another collection was made from the same site during 1995. Five seeds were collected from each of 50 plants.

Seedbanking for this species calls into question the protocol for establishing a conservation seedbank, as each plant may produce only 1200 seeds during its lifetime. Until germination tests provide more definite results, the Garden maintains a conservative approach to augmenting the seedbank it has established. Desert Botanical Garden has only 2 field seed collections, both obtained from a population occurring on privately owned land. The first collection was made in 1987 when 812 seeds were collected. The seeds appeared immature at the time of collection, and germination tests failed. The seeds had been immediately frozen following cleaning and counting, prior to establishing a baseline germination percentage. If the seeds were not fully mature, it is possible that freezing killed the developing embryos. The protocol for the storage process for Cactaceae is being re-examined at Desert Botanical Garden (DBG). Another collection was made from the same site during 1995. Five seeds were collected from each of 50 plants.

Despite intensive searching, this species is known only from 1 population in southeastern Arizona and 1 in adjacent Sonora, Mexico. Most of the plants are concentrated in small pockets of this tiny range, making the species especially vulnerable to cactus poachers; also potentially threatened by pesticides and mining.

The major threat to this species lies in its limited range and the scarcity of plants within that range. It would take only a small localized catastrophic event to decimate the species, or reduce its numbers to a point where it could no longer sustain its

Only three populations of this species are known in the US. All are located within walking distance from each other (USFWS 1993). A detailed census covering one square hectare was completed by Zimmerman (1978), who found approximately 470 plants.

The failure to germinate seeds collected from any of the plants, provided support to the idea that freezing may not be appropriate for some seeds of desert plants, notably members of Cactaceae. Experimentation with some other species of cactus has provided similar results. The protocol for the storage process for Cactaceae is being re-examined at Desert Botanical Garden (DBG). Another collection was made from the same site during 1995. Five seeds were collected from each of 50 plants. During 1999, DBG received 33 plants, each approximately 2 cm in diameter, from a private individual. These plants immediately flowered at the time they normally would have, and controlled cross-pollinations were conducted, producing 78 fruits and a total of 2827 seeds. The seeds were allowed to dry in the partially dry fruits, and then cleaned and counted by hand. They were stored in an airtight foil pouch after 6 weeks of drying at 63 degrees C. Germination tests have been conducted, resulting in 64% germination. Approximately 30 seedlings remain alive from this experiment. They are approximately 1 mm in diameter at 6 months old, and have developed the first two to three spine clusters.

Populations are located on privately owned, state and BLM land.

In its recovery plan for this species, the USFWS (1993) outlined management and restoration needs that include: creating a management plan, studying population biology and aspects of reproductive biology and ecology, protecting habitat through law enforcement, protection from pesticides, establishing new populations, and seed banking.

Seedbanking for this species calls into question the protocol for establishing a conservation seedbank, as each plant may produce only 1200 seeds during its lifetime. Until germination tests provide more definite results, the Garden maintains a conservative approach to augmenting the seedbank it has established. Desert Botanical Garden has only 2 field seed collections, both obtained from a population occurring on privately owned land. The first collection was made in 1987 when 812 seeds were collected. The seeds appeared immature at the time of collection, and germination tests failed. The seeds had been immediately frozen following cleaning and counting, prior to establishing a baseline germination percentage. If the seeds were not fully mature, it is possible that freezing killed the developing embryos.