North America Non-native Plant

Philadelphus Satsumanus

Botanical name: Philadelphus satsumanus

USDA symbol: PHSA13

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

Synonyms: Philadelphus yokohamae Dippel (PHYO)   

Philadelphus satsumanus: The Mysterious Mock Orange If you’ve stumbled upon the name Philadelphus satsumanus while researching plants for your garden, you’re not alone in finding limited information about this elusive species. This member of the mock orange family represents one of those botanical mysteries that keeps plant enthusiasts scratching their ...

Philadelphus satsumanus: The Mysterious Mock Orange

If you’ve stumbled upon the name Philadelphus satsumanus while researching plants for your garden, you’re not alone in finding limited information about this elusive species. This member of the mock orange family represents one of those botanical mysteries that keeps plant enthusiasts scratching their heads.

What We Know (And Don’t Know)

Philadelphus satsumanus belongs to the beloved mock orange genus, known for their fragrant white flowers that bloom in late spring and early summer. However, unlike its more famous cousins, this particular species remains shrouded in horticultural mystery. Also known by the synonym Philadelphus yokohamae, it appears to have connections to East Asia, particularly Japan, based on its nomenclature.

Unfortunately, reliable information about this species is extremely scarce in both scientific literature and horticultural sources. We don’t have clear data on its:

  • Common names
  • Exact native range
  • Growth habits and mature size
  • Specific care requirements
  • Availability in the nursery trade

The Challenge of Rare Species

When a plant species lacks documentation, it often indicates one of several scenarios: it may be extremely rare in cultivation, potentially extinct in the wild, or simply overlooked by the horticultural community. Without proper documentation, growing such plants becomes a gamble for home gardeners.

Better Alternatives for Your Garden

Rather than hunting for this botanical unicorn, consider these well-documented and readily available mock orange alternatives:

  • Philadelphus lewisii – Native to western North America, perfect for native plant gardens
  • Philadelphus coronarius – The classic European mock orange with intense fragrance
  • Philadelphus inodorus – A native southeastern US species, great for natural landscapes

If You’re Determined to Find It

Should you be absolutely set on tracking down Philadelphus satsumanus, here are some tips:

  • Contact specialized botanical gardens or arboreta
  • Reach out to plant collectors’ societies
  • Check with academic institutions that maintain rare plant collections
  • Ensure any plants are ethically and legally sourced

The Bottom Line

While the mystery of Philadelphus satsumanus might intrigue botanical enthusiasts, practical gardeners are better served choosing from the many well-documented mock orange species available. These proven performers will give you the fragrant flowers and easy care you’re looking for, without the uncertainty that comes with poorly documented plants.

Sometimes in gardening, it’s better to go with what works rather than chase botanical ghosts. Your garden (and your sanity) will thank you for it!

Philadelphus Satsumanus

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

Hydrangeaceae Dumort. - Hydrangea family

Genus

Philadelphus L. - mock orange

Species

Philadelphus satsumanus Siebold ex Miq.

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