North America Non-native Plant

Rosa ×iwara

Botanical name: Rosa ×iwara

USDA symbol: ROIW

Native status: Not native but doesn't reproduce and persist in the wild

Rosa ×iwara: The Mystery Rose That May Not Exist If you’ve stumbled across the name Rosa ×iwara in your gardening research, you might be scratching your head wondering what exactly this plant is. Well, you’re not alone – and there’s a good reason for the confusion. The Case of the ...

Rosa ×iwara: The Mystery Rose That May Not Exist

If you’ve stumbled across the name Rosa ×iwara in your gardening research, you might be scratching your head wondering what exactly this plant is. Well, you’re not alone – and there’s a good reason for the confusion.

The Case of the Missing Rose

Rosa ×iwara appears to be one of those botanical mysteries that occasionally pop up in plant databases and lists. Despite the × symbol indicating it should be a hybrid rose, there’s virtually no reliable information available about this particular plant name in botanical literature, horticultural guides, or scientific databases.

This could mean several things: it might be an extremely rare or regional hybrid that hasn’t been widely documented, it could be a name that was proposed but never officially established, or it might simply be a clerical error that has been propagated through various plant lists over time.

What We Don’t Know (Which is Everything)

Unfortunately, we can’t provide you with the usual gardening guidance because the essential information simply isn’t available:

  • Common names are unknown
  • Native range and geographical distribution are unclear
  • Growing conditions and care requirements are undocumented
  • Hardiness zones haven’t been established
  • Wildlife and pollinator benefits are unrecorded
  • Garden design applications are undefined

What Should Gardeners Do?

If you’re looking for a rose to add to your garden, we’d recommend focusing on well-documented species and cultivars instead. There are hundreds of beautiful, reliable rose options available, many of which offer excellent benefits for pollinators and wildlife.

For native plant enthusiasts, consider researching the native roses in your specific region. Many areas have wonderful indigenous rose species that are perfectly adapted to local conditions and provide crucial habitat for native wildlife.

The Takeaway

Sometimes in the plant world, names appear that lead to dead ends. Rosa ×iwara appears to be one of those cases. Rather than chasing after a plant that may not exist or be readily available, focus your gardening energy on the many proven, beautiful, and beneficial plants that are well-documented and accessible.

If you have specific information about Rosa ×iwara or have encountered this plant in cultivation, we’d love to hear from you – botanical mysteries like this are always intriguing to solve!

Rosa ×iwara

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Rosidae

Order

Rosales

Family

Rosaceae Juss. - Rose family

Genus

Rosa L. - rose

Species

Rosa ×iwara Siebold ex Regel

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA