North America Native Plant

Yerba De Alambre

Botanical name: Isachne angustifolia

USDA symbol: ISAN

Life cycle: perennial

Habit: grass

Native status: Native to Puerto Rico  

Yerba de Alambre: A Wetland Grass for Specialized Gardens If you’re looking for a native grass that thrives in the wettest spots of your Puerto Rican garden, yerba de alambre (Isachne angustifolia) might just be your new best friend. This charming little perennial grass has carved out a very specific ...

Yerba de Alambre: A Wetland Grass for Specialized Gardens

If you’re looking for a native grass that thrives in the wettest spots of your Puerto Rican garden, yerba de alambre (Isachne angustifolia) might just be your new best friend. This charming little perennial grass has carved out a very specific niche in the Caribbean landscape, and while it won’t work everywhere, it’s absolutely perfect for the right situation.

What Is Yerba de Alambre?

Yerba de alambre is a delicate, perennial grass native exclusively to Puerto Rico. Its botanical name, Isachne angustifolia, gives us a clue about its appearance – angustifolia means narrow-leaved, which perfectly describes this plant’s slender, grass-like foliage. As a graminoid (grass-like plant), it forms low, spreading tufts that create an attractive ground cover in the right conditions.

Where Does It Grow?

This little grass is a true Puerto Rican endemic, meaning you won’t find it growing wild anywhere else in the world. It’s perfectly adapted to the island’s tropical climate and specific wetland conditions.

The Wetland Specialist

Here’s where yerba de alambre gets really interesting – it’s what botanists call an obligate wetland plant. This fancy term simply means that this grass almost always grows in wetlands and requires consistently moist to wet soil conditions to thrive. Think of it as nature’s way of creating a plant specifically designed for the soggiest spots in your landscape.

Should You Plant Yerba de Alambre?

The answer depends entirely on what you’re trying to achieve and where you’re gardening. Here are some scenarios where this native grass shines:

  • You have a chronically wet area in your yard that other plants struggle with
  • You’re creating a rain garden or bioswale
  • You’re involved in wetland restoration projects
  • You want to support native Puerto Rican biodiversity
  • You need erosion control in wet areas

However, yerba de alambre definitely isn’t for everyone. If you’re looking for a drought-tolerant grass or something for dry, well-drained areas, this isn’t your plant.

Growing Conditions and Care

Successfully growing yerba de alambre is all about understanding its wetland nature:

  • Soil: Consistently moist to wet, boggy conditions
  • Water: Requires constant moisture – never let it dry out
  • Sunlight: Partial to full sun
  • Climate: USDA zones 10-11 (tropical conditions)
  • Temperature: Warm, humid tropical climate year-round

Planting and Maintenance Tips

If you’ve decided that yerba de alambre is right for your wetland garden, here’s how to help it thrive:

  • Plant in the wettest area of your landscape
  • Ensure the soil never dries out completely
  • Consider installing near water features, in rain gardens, or low-lying areas
  • Minimal fertilization needed – wetland soils are typically nutrient-rich
  • Allow it to spread naturally to form ground cover

Aesthetic Appeal

Don’t expect flashy flowers or dramatic foliage from yerba de alambre. Its beauty lies in its subtle, naturalistic appearance. The narrow leaves create a fine-textured, carpet-like effect that works beautifully in naturalized wetland settings. It’s the kind of plant that contributes to the overall harmony of a landscape rather than stealing the show.

Wildlife and Ecological Benefits

As a native grass, yerba de alambre plays an important role in Puerto Rico’s wetland ecosystems. While it’s wind-pollinated rather than relying on insect pollinators, it provides habitat structure and helps prevent soil erosion in sensitive wetland areas.

The Bottom Line

Yerba de alambre is definitely a specialist plant for specialist gardens. If you have the right wet conditions and want to support native Puerto Rican flora, it’s a wonderful choice. Just don’t try to force it into a typical garden setting – this little grass knows exactly what it needs and won’t compromise!

Remember, successful gardening is often about matching the right plant to the right place. For wetland gardens in Puerto Rico, yerba de alambre might just be the perfect fit you’ve been looking for.

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

Yerba De Alambre

Classification

Group

Monocot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Liliopsida - Monocotyledons

Subclass

Commelinidae

Order

Cyperales

Family

Poaceae Barnhart - Grass family

Genus

Isachne R. Br. - bloodgrass

Species

Isachne angustifolia Nash - yerba de alambre

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