Ibervillea tenuisecta (2010)

By Nikki Murdick (January 2010)

At the October meeting, I was excited to be the winner of a large Ibervillea tenuisecta. This plant is happily living in my dining room, although it lost all of the lovely green foliage when it came home with me. After about a month of dormancy it has now decided to leaf out again.

This plant is also known as the slimlobe globeberry or “deer apples.” It was first identified in 1903 by John Kunkel Small. In some of the earlier literature, you may find it listed under the names Maximowiczia lindheimeri var. tenuisecta or Sicydium lindheimeri var. tenuisectum.

I. tenuisecta is a member of the Cucurbitaceae family, which is native to North America and found in the U.S. Southwest, specifically Texas, Arizona and New Mexico, as well as in northern Mexico. As a member of the Cucubitaceae family, it has a large grey, somewhat smooth caudex that can grow to 35 centimeters or about 14 inches in diameter. From the caudex, it produces vines with deeply divided leaves that are yellow-green on top and hairy on the underside.

Ibervillea tenuisecta is a geophyte twining vine with the vine part being mostly deciduous annually. In native habitat, the caudex of I. tenuisecta remains underground with the leafy growth vining onto nearby plants. Thus, it is best to provide a trellis during its growing season.

This form of the plant is dioecious – there are both male and female plants. To get viable seeds, you must have one of each gender. The flowers are yellow, and when they appear, it looks as if they are attached to the end of a miniature zucchini. These blooms occur throughout June, July and August. If fruit appears, it is red when ripe and has been described as looking like scarlet marbles.

Ibervilleas prefers to have sun during their summer growing season. Care must be taken, though, to keep the caudex in the shade so it does not sunburn, while the leafy vines are in full sun. It prefers well-drained soil and regular watering when it is actively growing during the summer months. When dormant, it should be watered only when the soil becomes dry, otherwise it will easily rot. In order to keep the vine from dying back, Ibervillea tenuisecta should be kept in temperatures above 40 degrees F. However, the caudex can take lower temperatures for short periods of time.

If you are interested in this plant, you can find more information and photos at Birhmann’s Caudiciforms – http://www.bihrmann.com/caudiciforms/SUBS/ibe-ten-sub.asp