North America Native Plant

Sharp’s Leptohymenium Moss

Botanical name: Leptohymenium sharpii

USDA symbol: LESH4

Habit: nonvascular

Native status: Native to North America  

Synonyms: Hylocomium splendens (Hedw.) Schimp. var. tenue Sharp (HYSPT2)  ⚘  Mittenothamnium sharpii (H.A. Crum & L.E. Anderson) W.R. Buck (MISH2)  ⚘  Pterigynandrum sharpii H.A. Crum & L.E. Anderson (PTSH)  ⚘  Taxiphyllum sharpii (H.A. Crum & L.E. Anderson) H. Rob. (TASH)   

Sharp’s Leptohymenium Moss: A Critically Rare North American Bryophyte If you’ve stumbled across the name Sharp’s leptohymenium moss (Leptohymenium sharpii) in your botanical wanderings, you’ve encountered one of North America’s rarest moss species. This tiny green treasure is so uncommon that most gardeners will never see it in the wild, ...

Rare plant alert!

Region: Conservation status by state

Status: S1: Status is uncertain but is somewhere between the following rankings: Critically Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 5 or fewer occurrences or very few remaining individuals (<1,000) ⚘

Sharp’s Leptohymenium Moss: A Critically Rare North American Bryophyte

If you’ve stumbled across the name Sharp’s leptohymenium moss (Leptohymenium sharpii) in your botanical wanderings, you’ve encountered one of North America’s rarest moss species. This tiny green treasure is so uncommon that most gardeners will never see it in the wild, let alone in their backyard.

What Is Sharp’s Leptohymenium Moss?

Sharp’s leptohymenium moss is a bryophyte – part of that fascinating group of non-flowering plants that includes mosses, liverworts, and hornworts. Like its moss cousins, it’s a small, herbaceous plant that typically grows attached to solid surfaces like rocks, tree bark, or decaying wood rather than directly in soil.

This moss is native to North America, though its exact geographic distribution remains poorly documented – which isn’t surprising given its extreme rarity. What we do know is that it’s terrestrial, meaning it grows on land rather than in water.

A Conservation Concern

Here’s where things get serious: Sharp’s leptohymenium moss carries a Global Conservation Status of S1, which translates to Critically Imperiled. This designation means the species is at extreme risk of extinction due to its rarity, with typically five or fewer known occurrences and fewer than 1,000 individual plants remaining in the wild.

This critical status puts Sharp’s leptohymenium moss in the same conservation category as some of our most endangered wildlife species. Every individual plant matters for the survival of this species.

Why You Won’t Find It at the Garden Center

Unlike common garden mosses that you might cultivate for a woodland garden or green roof, Sharp’s leptohymenium moss is neither available for purchase nor appropriate for home cultivation. Its extreme rarity means that any collection from the wild could potentially harm the species’ survival chances.

Even if seeds or spores were available, we simply don’t have enough information about this moss’s specific growing requirements, preferred habitat conditions, or cultivation needs to successfully grow it in a garden setting.

The Role of Rare Mosses in Ecosystems

While you can’t grow Sharp’s leptohymenium moss in your garden, understanding its importance helps us appreciate the incredible diversity of plant life around us. Mosses like this one:

  • Help prevent soil erosion in their native habitats
  • Create microhabitats for tiny invertebrates and other organisms
  • Contribute to nutrient cycling in forest ecosystems
  • Serve as indicators of environmental health and air quality

What This Means for Gardeners

As native plant enthusiasts, we can support moss conservation by:

  • Learning to identify and appreciate common native mosses in our regions
  • Creating moss-friendly conditions in our gardens using locally abundant species
  • Supporting organizations that work to protect rare plant habitats
  • Never collecting rare plants from the wild

If you’re interested in incorporating mosses into your native garden design, focus on common species that are abundant in your area. Many regions have beautiful native mosses that can add texture and year-round green to shaded areas without putting rare species at risk.

A Reminder of Nature’s Fragility

Sharp’s leptohymenium moss serves as a powerful reminder that not every plant is destined for our gardens – and that’s perfectly okay. Some species are so rare and specialized that their greatest value lies in simply continuing to exist in their natural habitats.

The next time you’re exploring natural areas, take a moment to look closely at the small green carpets and cushions growing on rocks and logs. You’re witnessing an ancient lineage of plants that have been quietly doing their part to keep ecosystems healthy for millions of years. And who knows? With careful observation and a bit of luck, you might just spot something truly special – though probably not Sharp’s leptohymenium moss!

Sharp’s Leptohymenium Moss

Classification

Group

Moss

Kingdom

Plantae - Plants

Subkingdom
Superdivision
Division

Bryophyta - Mosses

Subdivision

Musci

Class

Bryopsida - True mosses

Subclass

Bryidae

Order

Hypnales

Family

Hylocomiaceae M. Fleisch.

Genus

Leptohymenium Schwägr. - leptohymenium moss

Species

Leptohymenium sharpii (H.A. Crum & L.E. Anderson) W.R. Buck & H.A. Crum - Sharp's leptohymenium moss

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