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Iris tridentata

Botanical Name: Iris tridentata (added by D. Kramb, 27-OCT-03)

Botanical Synonyms:

Iris tripetala (D. Kramb, 10-OCT-04)


Tripetalae (D. Kramb, 10-OCT-04)

Genus Iris, Subgenus Iris, Section Spathula, Subsection Apogon, Series Tripetalae (Victor W. Lambou, 272 Pine Lane, Crawfordville, FL 32327; Phone: 850-925-4477; Email: Vwak@msn.com, 15-JUN-13)

Common Names:

Savannah iris (D. Kramb, 15-JAN-06)

Since this species tends to be found in bogs, I'm not sure why some sources call it a savannah iris. (D. Kramb, 20-APR-06)

Savannah Iris, (Victor W. Lambou, 272 Pine Lane, Crawfordville, FL 32327; Phone: 850-925-4477; Email: Vwak@msn.com, 15-JUN-13)

Chromosome Count:


General Description:

Grows 12" to 28" tall with flowers that are blue-violet to dark violet and fragrant. (D. Kramb, 10-OCT-04)

In the late summer, fall and early winter the mature rhizomes will produce relatively thin stolons from a few inches to 12 or more inches in length, at the end of which will develop a rhizome with a small fan of leaves. The leaves on the mature rhizomes at this stage will be from ~20 to ~25 inches in length. As winter develops the leaves will become much shorter and in many of the clones will eventually have only small fans of leaves, an inch or so in length, and some will go completely dormant with no top growth evident at all. In late spring the leaves will elongate and blooming here will occur in May and sometimes continue to early June. Most of the Louisiana type irises will have finished blooming by the time tridentata blooming commences. In as far as I can ascertain, the new fans produced in the fall will not bloom the first year even though they may appear to be mature. The tridentata plants remain in active growth throughout the summer. Tridentata’s growth cycle seem to be the exact opposite of the Louisiana irises, i.e., the Louisiana irises are in active growth when the tridentata are not in active growth or are dormant and when the tridentata are in active growth, the Louisiana irises are not in active growth and may be semi-dormant. (D. Kramb, 14-JAN-06)

Distinguishing Features:

There's not really any other iris that this could be confused with. It's flowers are unique, and it's growth habit is too. The seeds could probably be confused with Louisiana irises or Iris virginica, though. (D. Kramb, 20-APR-06)

Preferred Habitat:

In the wild, tridentata are bog plants, at least the tridentata occurring in areas that drain into the Gulf of Mexico. I am not familiar with plants growing in areas draining into the Atlantic Ocean. Try to keep approximately an inch or so of water over the soil surface. I grow mine in plastic tubs with no drainage and they bloom every year under these conditions. (D. Kramb, 14-JAN-06)


At least Zone 6 (D. Kramb, 12-OCT-04)

This Iris has grown successfully for me for 3 years in northern Delaware (Zone 7). (G. Tepper, 30-NOV-08)

Native Range:

Southeastern USA (D. Kramb, 10-OCT-04)

Status in the Wild:


Commercial Availability:

Specialty nurseries, SIGNA seed exchange (D. Kramb, 14-JAN-06)

Sources Cited:

Info entered on 10-OCT-04 comes from the SIGNA Checklist of Iris Species. (D. Kramb, 10-OCT-04)

Info entered on 14-JAN-06 comes from a posting by V. W. Lambou on the Iris-Species mailing list on Yahoogroups, dated 13-AUG-2004. (D. Kramb, 14-JAN-06)

Lambou, V. W. 2013. Observations on Habit, Ecology, and Cultivation of the Savannah Iris, Iris tridentata. The Wet Acre, 9 pp. (www.thewetacre.com). (Victor W. Lambou, 272 Pine Lane, Crawfordville, FL 32327; Phone: 850-925-4477; Email: Vwak@msn.com, 15-JUN-13)

Additional Comments:

I postulate that if the tridentata is kept too dry during the summer, most of the young fans may not built up sufficient reserves of energy to bloom the next year and may need an additional year or years to build up sufficient reserves. The fact that tridentata seeds and Louisiana iris seeds are somewhat similar, may only be a parallel adaptation for utilizing the same method of seed dispersal. (D. Kramb, 14-JAN-06)

I have had success growing this Iris in moist clay-loam soil. It established quickly, blooms well for me and is quite vigorous. (G. Tepper, 30-NOV-08)

Publication available at www.thewetacre.com dealing with the habit, ecology, and cultivation of I. tridentata. (Victor W. Lambou, 272 Pine Lane, Crawfordville, FL 32327; Phone: 850-925-4477; Email: Vwak@msn.com, 15-JUN-13)

Where to buy it:

Iris City Gardens

SIGNA member!

Iris Haven

Joe Pye Weed's Garden

SIGNA member!

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