Iris

Iris are distinctive for their sword shaped foliage and rhizomes although a few species come from bulbs. Most species bloom in the spring to early summer. There are more than 200 different species with many being available for the home landscape. In addition, there are thousands of named cultivars.

The parts of the iris flower occur in groups of three. The sepals, or outer 3 parts of the flower, are the falling petals called the falls, which usually droop. The petal-like part of the fall is called the blade, the basal part is the haft. The inner parts, or upright petals, are called standards. Inside these are 3 more petal-like and very narrow organs called style arms.

There are many categories of iris, however, the most common ones in the landscape include four broad groups.

  1. PGC-P-Iris-crestata-2011-02Bearded Iris (also called pogons) have a fuzzy, often bright colored "beard" on each falling petal (i.e. fall).

  2. Beardless Iris (also called apogons) are lacking this feature.

  3. Crested Iris have a distinctive ridge or "crest" on the fall.

  4. Bulbous Iris do not have a rhizome like the others but rather survive as a bulb.

The iris is named for the Greek goddess of the rainbow. Many species are called "flags" because the sepals of the flowers hang out like banners.

Care and Culture of Iris - Iris for the Home Landscape

Common Name Flower
Type
Bulb or
Rhizome
Iris Hybrids Many Cultivars Various Various
I. aphylla Stool Iris Bearded  
I. bakerana  Baker Iris   Bulbous
I. bracteata Braeted Iris Beardless  
I. brevicaulis
(I. foliasa)
Lamance Iris Beardless  
I. bucharica Bokhara Iris   Bulbous
I. chamneiris Crimean Iris Bearded  
I. chrysographes Goldvein Iris Beardless  
I. cristata Crested Iris Crested rhizomes
I. danfordiae Danford Iris   Bulbous
I. detavayi Detavays Iris Beardless  
I. dichotoma Vesper Iris Beardless  
I. domestica      
I. douglasiana Douglas Iris Beardless  
I. ensata Japanese Water Iris    
I. flavissima Goldbeard Iris Bearded  
I. foetidissima Gladwin Iris Beardless  
I. forrestii Yunnan Iris Beardless  
I. fulva Copper Iris Beardless  
I. germanica German Iris Bearded  
I. giganticaerulea   Beardless  
I. gracilipes Slender Iris Crested  
I. hartwegii Foothill Iris Beardless  
I. hexagona Dixie Iris Beardless  
I. histrio Syrian Iris   Bulbous
I. histrioides Harput Iris   Bulbous
I. hoogiana Redbeard iris    
I. innominata   Beardless  
I. japonica Fringed Iris Crested  
I. kaempferi Japanese Iris Beardless  
I. korolkowii Redvein Iris Regelia  
I. lacustris Dwarf Crested Iris    
I. laevigata Rabbitear Iris Beardless  
I. macrosiphon Tube Iris Beardless  
I. meillta Tread Iris Bearded  
I. missouriensis Rocky Mountain Iris Beardless  
I. orientalis Oriental Iris Beardless  
I. paillda Sweet Iris Bearded  
I. persica Persian Iris   Bulbous
I. prismatica Cubeseed Iris Beardless  
I. pseudaconis Yellow Flag Beardless  
I. pseudo-pumila Tineo Iris Bearded  
I. pumila Dwarf Bearded Bearded  
I. purdyi Purdy Iris Beardless  
I. regalis   Beardless  
I. reticulata Netted Iris Reticulata Bulbous
I. rosenbaehiana Spinster Iris   Bulbous
I. sanguinea Iris    
I. setosa Arctic Iris Beardless  
I. siberica Siberian Iris Beardless  
I. spuria

Spurious Iris,
Seashore Iris

Beardless  
I. spurin halophylla   Beardless  
I. susiana Mourning Iris    
I. tectorum Roof Iris Crested  
I. tenax Oregon Iris Beardless  
I. tenuissima   Beardless  
I. tingitana Tangiers Iris   Bulbous
I. versicolor Blue Flag Beardless  
I. virginica Southern Blue Iris Beardless  
I. Wilsonii Wilson Iris Beardless  
I. xiphioides English Iris   Bulbous
I. xiphium Spanish Iris   Bulbous
Species Hgt
(in)
Flower
Color
Flower
Type
Rhizome
or Bulb
I. “Bearded hybrids”  8-36 Various Bearded Rhizome
I. cristata 6-9 Lavender Crested Rhizome
I. danfordiat 4-6 Yellow Beardless Bulbous
I. foetidissima 18-24 Lilac Beardless Rhizome
I. kaentpfèri 24-30 Various Beardless Rhizome
I. paillda 24-36 Violet Bearded Rhizome
I. pseudacorus 24-36 Yellow Beardless Rhizome
I. reticulata 4-6 Violet Beardless Bulbous
I. sibirica 24-36 Blue Beardless Rhizome
I. tectorum 12-18 Lilac Crested Rhizome
I. pema 4-6 Blue Beardless Rhizome
I. “Xiphium hybrids” 12-18 Various Beardless Bulbous

* Guides and Keys are from the book "Herbaceous Perennial Plants A Treatise on their Identification, Culture and Garden Attributes" by Dr Allan M. Armitage of the University of Georgia. Varsity Press, Athens, Georgia. 1989 ISBN 0-942375-00. More on Dr Armitage and his other books.

 

 

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