Pilosocereus tillianus

The Pilosocereus tillianus is indigenous to Mexico (Lagunillas), and Venezuela (Merida state). A columnar species, ribbed stems are cylindrical and erect. Juvenile stems initially take on a blue color eventually becoming bluish-green to glaucous green. 20 - 25 feathery, flexible spines erupt from each areola. They are yellow as juveniles and turn gray with time. Spines are not differentiated into radials and centrals. At full maturity, it can reach heights of up to 10'.

Interestingly, the Pilosocereus tillianus belongs to a predominantly outcrossing species, but partially self-compatible. Outcrossing refers to the crossing of different species that have no common ancestors. The practice of introducing unrelated genetic material into a breeding line increases genetic diversity. This boost in genetic diversity in return reduces the probability of an individual being subject to disease or genetic abnormalities. Outcrossing in the plant kingdom is usually enforced by self-incompatibility.

Curiously, the Pilosocereus tillianus produces flowers in discrete pulses. Botanists believe that this species may actually be exhibiting synchronous pulsed flowering, a very rare flowering pattern among angiosperms. Synchronous pulsed flowering is characterized as population-wide concerted flowering events separated by days with no or few open flowers. This flowering method is thought to be an evolved strategy that provides selective benefits by increasing outcrossing and by spreading out the risk of reproductive failure.

This is one, smart species!

Synonyms:

Pilosocereus lanuginosus (L.) Byles & G.D.Rowley
Cactus lanuginosus L.
Cephalocereus lanuginosus (L.) Britton & Rose
Cereus consolei Lem. in Borg
Pilocereus consolei Lem.
Pilosocereus backebergii (Weing.) Byles & G.D.Rowley
Cephalocereus backebergii (Weing.) Borg
Cephalocereus backebergii (Weing.) Buxb.
Cereus backebergii (Weing.) Backeb.
Pilocereus backebergii Weing.
Pilosocereus claroviridis (Backeb.) Byles & G.D.Rowley
Cephalocereus claroviridis (Backeb.) Borg
Cereus claroviridis Backeb.
Pilocereus claroviridis (Backeb.) Backeb.
Pilosocereus gironensis Rauh & Backeb. ex Byles & G.D.Rowley
Pilosocereus lanuginosus subs. colombianus (Rose) Guiggi
Cephalocereus columbianus Rose
Cereus colombianas (Rose) Vaupel
Cereus columbianus Vaupel
Pilocereus colombianus (Rose) Backeb.
Pilosocereus colombianus (Rose) Byles & G.D.Rowley
Pilosocereus columbianus: (Rose) Byles & G.D.Rowley
Pilosocereus lanuginosus subs. moritzianus (Otto ex Pfeiff.) Guiggi
Cephalocereus moritzianus (Otto) Britton & Rose
Cereus moritzianus Otto ex Pfeiff.
Pilosocereus moritzianus (Otto) Byles & G.D.Rowley
Pilosocereus tuberculosus Rauh & Backeb. ex Byles & G.D.Rowley
Pilosocereus tweedyanus (Britton & Rose) Byles & G.D.Rowley
Cephalocereus tweedyanus Britton & Rose
Cereus tweedyanus (Britton & Rose) Werderm. in Backeb.
Pilocereus tweedyanus (Britton & Rose) Backeb. in Backeb. & F.M.Knuth
Pilocereus tweedyanus (Britton & Rose) Backeb.
Pilosocereus lanuginosus subs. tillianus (R.Gruber & Schatzl) Guiggi