North America Native Plant

Riddell’s Spikemoss

Botanical name: Selaginella arenicola riddellii

USDA symbol: SEARR

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Selaginella arenicola Underw. var. riddellii (Van Eselt.) Waterf. (SEARR2)  âš˜  Selaginella riddellii Van Eselt. (SERI3)   

Riddell’s Spikemoss: A Rare Native Lycopod Worth Knowing Meet Riddell’s spikemoss (Selaginella arenicola riddellii), a fascinating little plant that’s neither moss nor fern, but something quite special in between. This perennial lycopod is a living link to some of Earth’s most ancient plant lineages, and if you’re lucky enough to ...

Rare plant alert!

Region: Arkansas

Status: S2: Status is uncertain but is somewhere between the following rankings: Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 6 to 20 occurrences or few remaining individuals (1,000 to 3,000) ⚘ Vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals ⚘

Region: Arkansas

Riddell’s Spikemoss: A Rare Native Lycopod Worth Knowing

Meet Riddell’s spikemoss (Selaginella arenicola riddellii), a fascinating little plant that’s neither moss nor fern, but something quite special in between. This perennial lycopod is a living link to some of Earth’s most ancient plant lineages, and if you’re lucky enough to spot one in the wild, you’re looking at a true botanical treasure.

What Exactly Is Riddell’s Spikemoss?

Don’t let the name fool you – Riddell’s spikemoss isn’t actually a moss at all! It’s a lycopod, which makes it more closely related to ferns than to true mosses. These remarkable plants are evolutionary survivors that have been around for hundreds of millions of years, making them some of the oldest vascular plants on our planet.

Classified as a forb, Riddell’s spikemoss is a vascular plant that lacks significant woody tissue above ground. Unlike trees and shrubs that develop thick, woody stems, this perennial plant keeps its growing buds at or below ground level, helping it survive through different seasons.

Where You’ll Find This Rare Beauty

Riddell’s spikemoss calls the southeastern United States home, with populations documented in Alabama, Arkansas, Georgia, Louisiana, Oklahoma, and Texas. However, don’t expect to stumble across it on every nature walk – this native plant is quite rare in much of its range.

A Conservation Concern

Here’s where things get serious: Riddell’s spikemoss is considered rare across its native range. In Alabama, it holds an S2 rarity status, meaning it’s imperiled and at high risk of extinction. Arkansas populations fare slightly better with an S3 status, but that still means the species is vulnerable.

What does this mean for gardeners and plant enthusiasts? If you’re interested in this species, it’s crucial to only obtain plants through responsible sources – never collect from wild populations. Better yet, consider this an opportunity to appreciate the plant in its natural habitat and support conservation efforts instead.

Is Riddell’s Spikemoss Beneficial in Gardens?

While we don’t have specific information about this subspecies’ role in garden ecosystems, lycopods in general can be interesting additions to specialized native plant collections. However, given its rarity status, Riddell’s spikemoss is better left to conservation efforts and natural habitats rather than home gardens.

If you’re drawn to ancient, unique plants for your landscape, consider exploring other native alternatives that are more common and readily available through ethical nursery sources.

Protecting Our Plant Heritage

Riddell’s spikemoss represents an important piece of our natural heritage. These ancient plants have survived ice ages, continental drift, and massive climate changes, but they’re now facing their greatest challenge yet: habitat loss and human pressure.

The best way to support Riddell’s spikemoss is to:

  • Learn to identify and appreciate it in wild settings
  • Support habitat conservation in the southeastern states
  • Choose abundant native alternatives for your garden projects
  • Spread awareness about rare native plants in your community

Sometimes the most meaningful way to connect with a rare plant is simply knowing it exists and doing our part to ensure it continues to thrive in the wild for future generations to discover and admire.

Riddell’s Spikemoss

Classification

Group

Lycopod

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision
Division

Lycopodiophyta - Lycopods

Subdivision
Class

Lycopodiopsida

Subclass
Order

Selaginellales

Family

Selaginellaceae Willk. - Spike-moss family

Genus

Selaginella P. Beauv. - spikemoss

Species

Selaginella arenicola Underw. - sand spikemoss

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