Cereus hildmannianus is one of several similar species of organ pipe cactus that found in South America, California and Arizona. These medium-sized cacti are nearly spineless and bloom selectively for only a few nights a year. The flowers unfold from a pod and bloom one evening, then shrivel into a fruit the next day. Used as a natural sensor they could guide desert farmers in planting crops such as corn, squash and beans for a spring harvest or for planting melons at the spring equinox. Analog methods of detection could include planting as hedges (it can grow prolifically) and using the Mk. 1 eyeball for approximating the equinox. This could have worked for Hohokam farmers without access to astronomer-priests. A digital system might use a low-resolution camera and use a prior distribution or frame referencing image processing technique to trigger scripted remote events.
While it’s cousin species only flower synchronously one night a year, it flowers over several nights. It has less fragrant blossoms and they shrink into a dragonfruit-like fruit. These cacti seem to display a biological light switch using a technique known as photomorphogenesis that is triggered by the plant’s photochrome system.
According to Devlin, Christie & Terry (2007) “timing of flowering in many species is governed by light. In this case, duration of light is the important factor. Lengthening days (or more strictly shortening nights) signal the approach of spring while shortening days (lengthening nights) signal the approach of winter. This regulation of flowering by light is mediated through interaction with an internal 24 h timekeeper known as the circadian clock to ensure that the flowering process is receptive to light during the evening.” This is dramatically expressed in C. hildmannianus.
Equipment: Canon T3, tripod, Polaroid timer, miscellaneous cameras.
Music is Ghosts I, 6 by NIN, Open Content License.