Culture
Winter hardy to USDA Zones 6 to 9 where it is best grown in humus-rich, moist but well-drained soils in part shade, dappled shade to almost full shade. Needs consistent moisture. Does poorly in heavy clay soils. Mulch in winter to protect plants, particularly from late spring frosts. Plant tubers about 3-4" deep. May be grown from seed, but may take 3-5 years before plant will flower. In the St. Louis area, it should be planted in a sheltered location. Plants of this species are considered to be paradioecious (separate male and female plants in which the active fertile flowers which emerge on the spadix each spring may be of a different sex from year to year depending primarily upon the health and vigor of the plant). Young plants or plants experiencing stresses or female plants in the year following flowering will usually produce only fertile male flowers whereas healthy plants that are several years old and not subject to stresses often produce only fertile female flowers. In any given year, the fertile spadix flowers will be either male or female but not both.
Noteworthy Characteristics
Arisaema engleri, commonly called cobra lily or Engler’s Chinese Jack-in-the-pulpit, is a tuberous woodland understory perennial that is native to certain forested areas of Hubei Province in China. It typically grows to 20” tall. Each tuber produces two broad leaves, both of which are divided into five dark green leaflets. A single flower structure emerges from the pseudostem in spring (April-May), each flower consisting of a showy, brownish-purple, pitcher-like bract lined with white and known as the spathe which subtends and encloses an inner, cylindrical, pencil-shaped purple flower spike known as the spadix. Tiny male or female flowers are located along the lower part of the spadix which rises slightly above the lip of the spathe in the shade of the arching and pointed spathe hood. Tiny female flowers are pollinated by insects, with the spathe and covering hood acting as a kettle trap. Plants go dormant in summer after flowering, except pollinated female flowers produce a vertical cluster of showy berries which ripen to bright red by late summer and become easily visible as soon as the spathe withers.
All plant parts contain calcium oxalate (same chemical as in Diffenbachia or dumb cane) and are poisonous.
Some authorities believe the within plant is a synonym of Arisaema bockii.
Genus name comes from Greek words aris meaning "arum" and aima meaning "red", in reference to the red-blotched leaves found on some species.
Specific epithet honors H.G.A. Engler (1844-1936), German botanist and plant collector.
Problems
No serious insect or disease problems.
Uses
This plant may be difficult to locate in commerce. It should be planted in groups for ornamental interest and to insure that pollination of female plants will occur with subsequent production of showy red berries. Best left undisturbed in shady woodland gardens, wild gardens or native plant areas.