Dietes - basics

Mary Sue Ittner
Mon, 13 Jul 2009 07:44:49 PDT
Dear Jim,

I smiled when you asked it our wiki photos are accurate and correctly 
named. I believe the wiki page to be correct as it has been carefully 
researched by me as I wanted to be sure what those plants were that grow 
all over the place in California and bloom for such a long time. 
Interestingly these are summer rainfall plants and California is a winter 
rainfall place which just shows you that common sense rules about what 
shouldn't grow well sometimes needs to be tested.

Kew accepts these species:
Dietes bicolor (Steud.) Sweet ex Klatt, Linnaea 34: 584 (1866)
Dietes butcheriana Gerstner, J. S. African Bot. 9: 149 (1943),
Dietes flavida Oberm., Fl. Pl. Africa 38: t. 1488 (1967)
Dietes grandiflora N.E.Br., J. Linn. Soc., Bot. 48: 35 (1928)
Dietes iridioides (L.) Sweet, Hort. Brit., ed. 2: 497 (1830)
Dietes robinsoniana (F.Muell.) Klatt, Abh. Naturf. Ges. Halle 15: 374 (1882).

We have four of them pictured on the wiki. Those other two species are 
pictured in the Pooley book, A Field Guide to WildFlowers Kwazulu-Natal and 
the Eastern Region.  Dietes vegeta is a synonym Kew says for D. iridioides. 
On the other hand Kew also says that another synonym for Dietes vegeta is 
Moraea vegeta which is an entirely different plant with absolutely no 
resemblance to Dietes iridioides at all. Dietes are rhizomatous plants. 
Moraea vegeta is a very short plant that grows from a corm.

The always excellent (with Rachel Saunders as editor) IBSA bulletin has an 
article by Graham Duncan in the latest issue describing a new color form of 
Dietes bicolor that he believes will be an excellent garden plant if 
watered regularly. He describes Dietes bicolor and Dietes grandiflora as 
being important landscape plants in South Africa, growing in sun or light 
shade, in almost any soil, surviving harsh conditions like roadside 
plantings and growing well in boggy situations and once established long 
periods of drought. As for D. butcheriana and D. iridioides, he states 
their small flowers are not as showy, but they will grow well in shade and 
the latter can be used as a ground cover under trees as it grows rapidly. 
D. butcheriana occurs in the mistbelt evergreen forest and has beautiful 
fans of very broad, bright green leaves.  Dietes flavida has light yellow 
flowers and he describes it as an excellent choice for its leaves placed in 
clumps towards the rear of sunny or semi-shaded borders. D. robinsoniana is 
native to an island off Australia and he describes it as a handsome garden 
plant for full sun. Some forms of Dietes iridioides can withstand sub-zero 
temperatures for short periods, but this genus is considered a tender genus.

The new form of Dietes bicolor described in the article found growing near 
the Mzamba River in the Eastern Cape has creamy inner and outer tepals with 
the outer tepals each having a prominent, semi-circular dark brown or 
almost black nectar guide near the base outlined with bright orange, with 
small, bright orange dots on the tepal claw that curves downwards toward 
the center of the flower. Comparing the picture in the bulletin with the 
one on the wiki in your mind substitute the black in the wiki pictures for 

Mary Sue

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