Stems with pale rows of areoles
The regional Bajío flora describes dark green stems with 5–6 ribs and elongate, confluent areoles. Branching begins near the base. Adjacent areoles form pale bands along the rib crests. [Arias and Aquino 2019]
Flowers and fruits
The regional account records flowers 2.5–4 cm long, with white or red inner tepals. The red fruits contain red pulp and split irregularly. [Arias and Aquino 2019]
Habitat and living fences
In Guanajuato and Querétaro the species occurs in xeric scrub and seasonally dry tropical forest at 750–2300 m. The reported February-to-May flowering period applies to this region. Plants are also grown as living fences. [Arias and Aquino 2019]
Cultivation under protection
The RHS recommends full sun and a sharply draining cactus mix. Watering is moderate during growth and the plants are kept dry in winter. Containers are maintained under glass or overwintered in a greenhouse. Documented propagation methods include spring sowing and summer stem-tip cuttings. [1-WWW]
Nocturnal and diurnal pollination
At Zapotitlán Salinas in central Mexico, researchers examined red flowers that began opening late in the evening. Full opening occurred at night, and flowers remained open the following day. Nectar was available both to nocturnal bats and to hummingbirds visiting by day. In the observations, maximum nectar secretion occurred in the morning. Flower opening, pollen release and stigma receptivity therefore created a period accessible to different animals. [Dar et al. 2006]
Flowers accessible only to night visitors or only to day visitors produced fewer fruits than flowers accessible throughout the day and night. Hand cross-pollination also produced high fruit set. Self-pollinated flowers produced no fruits. The results support the importance of pollen from other individuals and the complementary contributions of bats and hummingbirds in the population studied. [Dar et al. 2006]
A documented armoured scale on stems
Lepidosaphes beckii was recorded on plants described as Pachycereus marginatus at two localities in San Luis Potosí. Identification of the armoured scale relied on adult female characters. Insects occurred mainly on shaded stem regions, with yellowish patches around abundant colonies. The report documents a host and symptoms at particular Mexican sites. [Heinz-Castro et al. 2021]
Conservation assessment under a former name
POWO displays an IUCN assessment made under Pachycereus marginatus with category DD, Data Deficient. This category indicates a need for better information to assess extinction risk. It refers to the official Red List assessment linked to the species. [2-WWW]
Related articles
Materials from the author's archive
The species also appears in Konrad Szychowski's private material archive. [Schumann 1890] [Kreuzinger 1935]
Synonyms and names in the literature
Cereus marginatus · Pachycereus marginatus · Lemaireocereus marginatus · Stenocereus marginatus · Lophocereus marginatus · Cereus cupulatus · Cereus geminatus · Cereus gemmatus · Cereus incrustans · Cereus incrustatus · Cereus marginatus f. gibbosus · Cereus marginatus var. cristatus · Cereus marginatus var. monstrosus · Cereus mirbelii · Echinopsis gemmata · Lemaireocereus marginatus var. gemmatus · Lemaireocereus marginatus var. incrustatus · Marginatocereus marginatus var. oaxacensis · Pachycereus marginatus f. gibbosus · Pachycereus marginatus var. gemmatus · Pachycereus marginatus var. oaxacensis · Stenocereus marginatus var. gemmatus [2-WWW]