Jack-in-the-pulpit (Arisaema triphyllum
) is a distinctive, stemless plant that predominately grows in the woods. It's fruits are a mass of brilliant red or scarlet berries.
It displays a distinctive cycle of growth and development in which not only the age of the plant but also the conditions and limitations of its environment determine its relative gender and also its potential fertility. A seedling growing either from a fertilized seed or from a vegetative cormlet will spend from four to six years in a pre-reproductive, vegetative form.
As sufficient size is reached after these immature, growth years, the first flowers produced will be male, pollen producing flowers. As the plant continues to grow, though, through subsequent years the larger and larger spadix will begin to produce female flowers and thus then be able to produce seeds and fruit. Increases in nutrient availability or habitat quality will accelerate the transition of male plants into female plants. Decreases, though, in nutrients or habitat quality, or impacting environmental stresses, will cause female plants to revert back to their earlier male form or even back into their pre-flowering, vegetative state. After pollination, the spathe dies back revealing a cluster of green, berry-like fruit attached to the stalk of the spadix. These fruit turn bright red as they ripen on into the autumn. Each fruit contains a maximum of six ovules, but, on average, only one or two seeds. A. triphyllum
flowers consist of a three inch long, columnar structure called the spadix on which the many, tiny, male and female flowers are located. The spathe can range in color from green to purple. The flowers are located at the base of the spadex.
contains toxic levels of oxalic acid and asparagines within its tissues. The roots, in particular, have very high levels of these chemicals. The berries cause physical abrasions in the mucous membranes resulting from the crystals of calcium oxalate.