North America Native Plant

Ravine Midsorus Fern

Botanical name: Blechnum divergens

USDA symbol: BLDI

Life cycle: perennial

Habit: forb

Native status: Native to Puerto Rico  

Synonyms: Struthiopteris exaltata (Fée) Broadh. (STEX2)   

Ravine Midsorus Fern: A Caribbean Native for Wet, Shady Spots If you’re gardening in Puerto Rico or other tropical Caribbean locations and have a consistently moist, shady spot that needs some green magic, meet the ravine midsorus fern (Blechnum divergens). This native beauty might just be the perfect solution for ...

Ravine Midsorus Fern: A Caribbean Native for Wet, Shady Spots

If you’re gardening in Puerto Rico or other tropical Caribbean locations and have a consistently moist, shady spot that needs some green magic, meet the ravine midsorus fern (Blechnum divergens). This native beauty might just be the perfect solution for those tricky wet areas where many plants fear to tread.

What Makes This Fern Special?

The ravine midsorus fern is a true Caribbean native, calling Puerto Rico home. As a perennial fern, it provides year-round greenery and structure to your landscape. What sets this fern apart is its love affair with water – it’s classified as an obligate wetland plant, meaning it almost always grows in wet conditions in nature.

Don’t let the scientific name Blechnum divergens intimidate you. This fern is also known by the synonym Struthiopteris exaltata, but honestly, ravine midsorus fern rolls off the tongue much easier!

Where Does It Grow?

This fern is native to Puerto Rico, where it thrives in the island’s humid, tropical climate. If you’re gardening in this region, you’re working with a plant that truly belongs in your landscape.

Perfect Spots in Your Garden

The ravine midsorus fern is your go-to choice for:

  • Shade gardens that stay consistently moist
  • Bog gardens or rain gardens
  • Areas near water features or natural streams
  • Understory plantings in tropical landscapes
  • Wetland restoration projects

Growing Conditions That Make It Happy

Think of this fern as the plant equivalent of someone who loves long, steamy showers. It thrives in:

  • Partial to full shade (direct sun is a no-go)
  • Consistently moist to wet soil
  • High humidity environments
  • USDA hardiness zones 10-11

If you’re outside these tropical zones, this fern isn’t going to be happy outdoors year-round. It’s definitely a warm-climate specialist.

Planting and Care Tips

The key to success with ravine midsorus fern is remembering its wetland nature:

  • Plant in areas that naturally collect and hold water
  • Ensure soil never dries out completely
  • Protect from strong winds that can dry out fronds
  • Mulch around the base to help retain moisture
  • Choose locations with consistent shade throughout the day

Wildlife and Ecosystem Benefits

While ferns don’t produce flowers to attract pollinators, they play important roles in their native ecosystems. The ravine midsorus fern provides shelter for small wildlife and helps stabilize soil in wet areas, preventing erosion. By choosing native plants like this fern, you’re supporting the local ecosystem that evolved alongside these species.

Is This Fern Right for Your Garden?

The ravine midsorus fern is an excellent choice if you’re gardening in Puerto Rico and have the right conditions. It’s particularly valuable for:

  • Gardeners dealing with persistently wet, shady areas
  • Those interested in native plant gardening
  • Anyone working on wetland restoration or rain garden projects
  • Tropical gardeners looking for reliable, low-maintenance understory plants

However, this fern won’t work for you if you have dry conditions, need a sun-loving plant, or garden outside tropical zones. It’s definitely a specialist plant for specific conditions.

The Bottom Line

The ravine midsorus fern is a fantastic choice for the right gardener in the right place. If you’re in Puerto Rico with a wet, shady spot that needs some native green goodness, this fern could be exactly what you’re looking for. Just remember – keep it moist, keep it shaded, and it’ll reward you with lush, tropical beauty year-round.

Wetland Status

The rule of seasoned gardeners and landscapers is to choose the "right plant for the right place" matching plants to their ideal growing conditions, so they'll thrive with less work and fewer inputs. But the simplicity of this catchphrase conceals how tricky plant selection is. While tags list watering requirements, there's more to the story.

Knowing a plant's wetland status can simplify the process by revealing the interaction between plants, water, and soil. Surprisingly, many popular landscape plants are wetland species! And what may be a wetland plant in one area, in another it might thrive in drier conditions. Also, it helps you make smarter gardening choices and grow healthy plants with less care and feeding, saving you time, frustration, and money while producing an attractive garden with greater ecological benefits.

Regions
Status
Moisture Conditions

Caribbean

OBL

Obligate Wetland - Plants with this status almost always occurs in wetlands

Ravine Midsorus Fern

Classification

Group

Fern

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision
Division

Pteridophyta - Ferns

Subdivision
Class

Filicopsida

Subclass
Order

Polypodiales

Family

Blechnaceae Newman - Chain Fern family

Genus

Blechnum L. - midsorus fern

Species

Blechnum divergens (Kunze) Mett. - ravine midsorus fern

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