You can observe many light associated responses by growing houseplants. While these are not the plants that Dr. Marie Clark Taylor used in her research, they are plants that can be enjoyed for their curiosity, beauty and with appreciation for the subject matter that played an important role in an extraordinary career. Our knowledge of the environment and care details that allow a plant to survive in the inhospitable circumstances of an indoor space are a legacy of the research of botanists like Dr. Taylor.
There are houseplants that you may already be familiar with that demonstrate some of the plant world's exciting variations in light response.
Outside our homes, we are accustomed to plants responding to increased hours of sunlight with spring or summer flowers. But holiday cactus (Schlumbergera truncata) is a plant with a short-day photoperiod, that is to say it will only bloom when daylight declines and there are a minimum of 14 hours of uninterrupted darkness per day. When a plant owner is having trouble encouraging a holiday cactus to flower again, it is often because the plant is exposed to light from street lamps or ambient light in the home that prevents it from perceiving the short-day photoperiod.
Growing Schlumbergera truncata is an opportunity to experience for ourselves the impact of photoperiodicity, the process studied by Dr. Taylor, and appreciate her passion for hands on learning through living plants. For details on growing a Schlumbergera truncata (holiday cactus) in your home, select the Growing Holiday Cactus Tab at the top of this page.
Both flowers and leaves of false shamrock houseplants (Oxalis triangularis) fold at night, a phenomenon called nyctinasty, movement related to the onset of darkness. Nyctinasty is a circadian light response rather than an example of photomorphogenesis. Unlike photoperiodicity, nastic movement is not related to growth in the plant, but is a temporary posture the plant assumes in association with change in stimuli. Nyctinasty is regulated by a circadian clock, a natural biochemical process in the plant that anticipates daily light cycles.
Growing Oxalis triangularis offers the chance to observe the light associated phenomena of nastic movement. Botanists and horticulturalists have observed the plant's relationship to day and night but the evolutionary reason for folding up at night is not entirely understood. It may be related to conserving warmth, removing water, avoiding photoperiodic interruption caused by moon cycles or hiding the leaf surface from herbivores. For details on growing false shamrock (Oxalis triangularis) houseplant in your home, select the Growing False Shamrock Tab at the top of this page.
