How much sun does Limestone Adder's-tongue need?

Limestone Adder's-tongue grows best in part shade conditions.

When does Limestone Adder's-tongue bloom?

Limestone Adder's-tongue blooms in May and June.

Where is Limestone Adder's-tongue native?

Limestone Adder's-tongue (Ophioglossum engelmannii) is native to AL, AR, AZ, FL and 18 more states, per the World Checklist of Vascular Plants (Kew).

Is Limestone Adder's-tongue HOA-friendly?

Limestone Adder's-tongue takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.

Limestone Adder's-tongue

Name: Pollinator Patch
Author: Pollinator Patch

Ophioglossum engelmannii

Last reviewed: August 2026

Toxicity unknown

Limestone Adder's-tongue (Ophioglossum engelmannii) is not listed by the ASPCA Animal Poison Control Center (opens in new tab) or the other sources we check, so we have no verdict for it either way. Absence from those lists is not a clearance. If your pet shows symptoms after eating any plant, call the ASPCA at (888) 426-4435.

Light

part shade

Water

medium

Size

2"–8" H × 2"–6" W

Bloom

May, Jun

Native to

AL, AR, AZ, FL and 18 more states

Before you buy

Your city may pay you to plant this

Cities and water utilities offer rebates for replacing lawn with native and water-wise plants. We track 452 programs across 44 states, each with a link to the provider and the date we last checked it.

Find rebates in your area

Browse plants for this ecoregion

Central Great Plains Great Plains Cross Timbers Edwards Plateau Texas Blackland Prairies East Central Texas Plains Western Gulf Coastal Plain South Central Plains Eastern Temperate Forests Ozark Highlands Central Irregular Plains Western Corn Belt Plains Southeastern Plains Ridge and Valley Interior Plateau Interior River Valleys and Hills Southern Coastal Plain

Limestone adder's-tongue is a tiny, unusual fern that produces a single small leaf and a distinctive spore-bearing stalk in late spring. This diminutive native grows only 2-8 inches tall and prefers partially shaded areas with consistent moisture. It goes completely dormant in summer, disappearing until the following spring.

In an HOA neighborhood

Limestone Adder's-tongue takes more care to keep looking intentional in a front yard. Maintenance level: low. Consider it for backyard or mid-zone beds rather than the street edge.

Works well in: backyard only.

Extremely small and can appear as weeds
Completely dormant most of growing season
May be mistaken for lawn weeds when present

Wildlife value

As a fern, this species does not attract pollinators but provides habitat for small soil organisms and adds to native plant diversity in woodland gardens.

Common questions

How much sun does Limestone Adder's-tongue need?: Limestone Adder's-tongue grows best in part shade conditions.
When does Limestone Adder's-tongue bloom?: Limestone Adder's-tongue blooms in May and June.
Where is Limestone Adder's-tongue native?: Limestone Adder's-tongue (Ophioglossum engelmannii) is native to AL, AR, AZ, FL and 18 more states, per the World Checklist of Vascular Plants (Kew).
Is Limestone Adder's-tongue HOA-friendly?: Limestone Adder's-tongue takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.

Native range data from the World Checklist of Vascular Plants (Kew). Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.

If something looks wrong

Common plant problems, and what to check first

These come up on almost any plant. Each guide lists the likely causes in the order they are worth ruling out, with one thing to check before you act on any of them, and links to the source it came from.

See all plant problem guides

Ready to grow Limestone Adder's-tongue? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.

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