Davallia mariesii (Drynaria rhizomae) in TCM: Benefits, Uses, and More

Studies show that Davallia mariesii (also known as Gusuibu) has antioxidant, neuroprotective, antiviral (against influenza A), and anti-allergic properties. These effects may come from its ability to neutralize free radicals, protect nerve cells, inhibit viral infections, and reduce allergic reactions.
In traditional Chinese medicine, Gusuibu is used to treat bone-related issues like osteoporosis and inflammation.
There is limited information on its safety and toxicity, but it is generally considered safe when used appropriately. It’s best to use it under professional guidance to avoid potential interactions.
In Western countries, Davallia mariesii is mainly grown as an ornamental plant rather than used for medicinal purposes.

If you’ve ever wondered about the hidden gems of Traditional Chinese Medicine (TCM), Davallia mariesii, known as 骨碎补 (Gǔsuìbǔ) or Drynaria rhizomae, might catch your attention. This humble fern, often called Fortune’s Drynaria Rhizome or simply Gusuibu, has been a go-to remedy in TCM for centuries, especially for strengthening bones and speeding up recovery from injuries.

But what exactly makes this herb so special? In this article, we’ll dive into its traditional uses, modern benefits backed by science, how to use it, and what to watch out for—all explained in a way that’s easy to grasp, whether you’re a health enthusiast or just curious.

Table of Contents

What Is Davallia mariesii?

Davallia mariesii 海州骨碎補 — image: Wikimedia Commons

Picture a fern growing on rocky cliffs or tree trunks in the warm, humid regions of southern China—like Yunnan, Guangxi, and Guangdong. That’s Davallia mariesii, a plant with a long history in TCM. Its dried rhizome (root) is the star of the show, harvested year-round, cleaned, and often sliced or processed for medicinal use¹.

Appearance: The rhizome is flat, elongated, and slightly curved, about 5–15 cm long and 1–1.5 cm wide. It’s covered in soft, dark brown to blackish scales that look a bit like fur. When processed, it might turn a lighter brown, with small yellow dots (vascular bundles) visible when you break it open.
Taste and Nature: In TCM terms, it’s bitter and warm, targeting the liver and kidney meridians—key players in bone health and energy².

Think of it as nature’s version of a “bone fixer”—in fact, its Chinese name, 骨碎补, literally means “bone-mending herb.”

Traditional Uses in TCM

For hundreds of years, Davallia mariesii has been a trusted ally in TCM, especially for anything bone-related. Here’s how it’s been used traditionally:

Bone and Joint Support: It’s famous for strengthening bones and teeth, helping with issues like osteoporosis, loose teeth, or weak knees and lower back—symptoms often tied to kidney deficiency in TCM³.
Injury Recovery: Got a sprain or fracture? This herb is traditionally used to ease pain, reduce swelling, and help tissues heal faster after a fall or injury⁴.
Kidney Boost: By nourishing the kidneys (which TCM links to bone strength), it tackles problems like fatigue, leg weakness, and even ear ringing or hearing loss⁵.
Skin Relief: Applied externally, it’s said to soothe itchy rashes, fade spots, or even help with conditions like vitiligo or hair loss⁶.

Ancient texts back this up. For example, the Ben Cao Gang Mu (a classic Chinese herbal text from the 16th century) suggests using it with pig kidney to treat ear ringing and toothaches⁷—pretty creative, right?

Summary: Davallia mariesii has been used in TCM for centuries. It helps with bone and joint issues, injury recovery, kidney problems, and skin conditions. Ancient texts like Ben Cao Gang Mu support its traditional uses.

Science-Backed Benefits

Modern research is starting to catch up with tradition, revealing that Davallia mariesii does more than just mend bones. Here’s what studies have found:

Bone Health: Research shows it promotes calcium absorption in bones and improves blood calcium and phosphorus levels, aiding fracture healing and possibly slowing osteoporosis⁸. It’s like giving your skeleton a little extra TLC!
Antioxidant Power: Extracts from the herb fight off free radicals—those pesky molecules that damage cells—potentially supporting overall health and slowing aging⁹.
Neuroprotection: It may shield nerve cells from damage, hinting at benefits for conditions like Parkinson’s disease¹⁰.
Antiviral Effects: Lab studies suggest it can combat influenza A, making it a natural antiviral contender¹¹.
Anti-Allergy Action: It reduces histamine release, which could help with allergic reactions like rhinitis or skin irritation¹².

The magic lies in its compounds—like naringin (found in citrus fruits) and protocatechuic acid—which pack an antioxidant and anti-inflammatory punch.

How to Use Davallia mariesii

Ready to give it a try? Davallia mariesii can be used in a couple of ways, but always check with a TCM practitioner or doctor first. Here’s the rundown¹³:

Internal Use:
- Decoction: Boil 3–9 grams of the dried rhizome in water for 20–30 minutes to make a tea. Sip it to ease bone pain or boost kidney strength.
- Powder: Grind it into a powder or take it in capsules for convenience.
External Use:
- Poultice: Mix the powder with water to form a paste and apply it to bruises, swollen joints, or itchy skin.
- Ointment: Some blend it into creams for skin conditions like vitiligo.

Pro Tip: Avoid using copper or iron pots to cook it—TCM tradition says they might mess with its properties. Stick to ceramic or stainless steel.

Risks and Side Effects

While Davallia mariesii is generally safe when used correctly, it’s not for everyone. Here’s what to watch out for¹⁴:

Too Warm for Some: Its “warm” nature might worsen symptoms like night sweats, dry skin, or irritability if you’re prone to “yin deficiency” or “internal heat” in TCM terms.
Pregnancy Caution: It can stimulate blood flow, so pregnant women or those with bleeding issues should steer clear unless advised otherwise.
Limited Data: Modern studies are promising but scarce on long-term safety or drug interactions.

Heads-Up: If you’re on medications or have a health condition, talk to a pro before diving in. Better safe than sorry!

Davallia mariesii Beyond TCM

In the West, Davallia mariesii is better known as a decorative plant—think “squirrel’s foot fern” with its fuzzy rhizomes adorning homes and gardens¹⁵. But as herbal medicine gains traction, its TCM benefits might just catch on globally.

Quick FAQs

Got questions? We’ve got answers:

What’s it mainly used for in TCM?
Strengthening bones, healing injuries, and supporting kidney health—plus some skin perks when used topically.

Can it help with osteoporosis?
Traditionally, yes, and studies suggest it boosts bone calcium uptake. Still, pair it with a doctor’s advice for best results.

Is it safe for everyone?
Not quite. Avoid it if you’re pregnant, have bleeding disorders, or feel “overheated” (think dry mouth or night sweats).

How do I make it at home?
Boil 3–9 grams of the rhizome in water for a tea, or grind it into a paste for skin use. Simple, but follow a pro’s guidance.

The Bottom Line

Davallia mariesii, or 骨碎补, is a standout in Traditional Chinese Medicine, celebrated for mending bones, easing pain, and boosting vitality. From its roots in ancient healing to modern studies highlighting its antioxidant, antiviral, and bone-supporting powers, this herb offers a natural way to care for your body. Whether you’re sipping it as a tea or slapping it on a bruise, it’s a versatile remedy—just be sure to use it wisely with expert input. Who knew a little fern could pack such a punch?