It's the same habitat where we searched for moonworts last month. At that time, it was too early, but now they are here. However, this is not always the case. The landscape, once a military training ground about 30 years ago and later considered for a golf course, has become a unique place thanks to dedicated conservation efforts. Today it provides favorable conditions for the tiny fern we sought last month — least moonwort (Botrychium simplex).

Located just 400 meters from the Baltic Sea shore in Nemirseta, this area hosts one of the largest populations of B. simplex in Europe. Here B. simplex is accompanied with Early hair grass (Aira praecox) and Sand sedge (Carex arenaria) the characteristic species to The Carici arenariae-Airetum praecocis association, is classified as extremely rare and threatened by extinction due to succession.

It's intriguing to ponder the conditions within this habitat that gave rise to the existence of rare and delicate life forms. In what ways do these delicate life forms support life?

Three botanists Radvile, Anita and Darija search for B. simplex by crawling on hands and knees, counting this year's population. It’s fascinating to observe how each plant offers a unique entry point, inviting a different approach to its observation, field survey. What is it about this relationship that prompts busy botanists to eagerly spend their free time with the tiny fern creature?

This year, the total count exceeded 1,700.

Finding B. simplex is often like searching for a needle in a haystack. These elusive little moonworts can spend years underground, completing their entire life cycle without ever emerging. When they do finally surface, they are visible for only a month around mid-summer.

The part visible above ground is called the sporophyte. In the picture below, you can see a teeny-tiny, newly emerged sporophyte.

Passersby are around. Some stop to take a break from their journeys and ask what we're doing. We explore B. simplex, and they observe us. It's intriguing to watch them as well. What do they ask? How do they react? How do they perceive why/what's important?

B. simplex in Europe for the first time was found near Klaipėda (then Memel) nearly two hundred years ago. Pharmacist Wilhelm Kannenberg discovered unidentified moonworts in the area, collected herbarium specimens, and almost three decades later, Ernst Klinsmann described a new species, naming it Botrychium kannenbergii.

In North America, B. simplex had been described almost three decades earlier than B. kannenbergii, thus giving the name B. simplex priority.

Fast-forward to 2019, ecologist Erlandas Paplauskis discovered a population of B. simplex in Nemirseta. This discovery echos Kannenberg's pioneering work and continues the legacy of botanical exploration in the region. Until then, it was believed to have been long extinct. What were the conditions that allowed them to appear again after long period of time?

DISCOVERY AND REDISCOVERY

B. simplex is able to alter its physical form and structure in response to the shifting whispers of its environment. Such adaptability allows it to change shape, size, and organization, enhancing its chances of survival and reproduction in diverse conditions. This characterisation is called high morphological plasticity.

How are we changed by our unit of survival, and how do we shape it?

Below, B. simplex is busy cooking spores in round capsules called sporangia.

A LITTLE BIT OF SHAPE-SHIFTER

Each sporangium holds approximately 2,000 spores. It disperses over distances ranging from a few centimeters to several meters. The spores are resilient waiting for the right conditions — moisture and mycorrhizal associations — to germinate and grow into new plants. Researchers study how these spores travel through wind and even how they may be dispersed by animals, thanks to their protective, thick walls that aid in survival.

Moonwort spores have also become part of folklore and legend. In medieval Europe, it was believed that moonwort spores could mysteriously remove the shoes from a knight's horse as it galloped through a meadow. The same spores, blown through a keyhole, were said to unlock doors or render people invisible. What about that?

Spores ready for new life adventures. ↓

Soil sample collection is important for a better understanding of the B. simplex population structure above and below ground and their relationships with other individuals in the community.

In this location, B. simplex is found alongside two other allies from the same fern family: leathery moonwort (Botrychium multifidum) and adder's-tongue (Ophioglossum vulgatum).

O.vulgatum sporophytes grow intermixed with B. simplex.

The larger part of the B. multifidum population, which is quite abundant, grows 100–150 meters away from B. simplex.

Much of B. simplex's life cycle remains hidden underground. To better understand this subterranean world, soil samples of 10 x 10 cm ("cakes") are further explored in the lab.

Underground, B. simplex spores travel through water and soil's freeze-thaw cycles to grow into young plants called gametophytes. These independent gametophytes quickly partner with a specific fungus to survive.

For years, the gametophyte maintains this partnership until it reproduces by making eggs and sperm. The sperm swims through the soil to fertilize an egg, beginning a new sporophyte, the moonwort we see above the ground. Later, it produces spores, and the cycle continues.

The gametophyte could be referred to as the "fern flower" due to its resemblance to the reproductive cycle of a typical flowering plant.

And here it is! The gametophyte — the "fern flower"! ↓

LIFE CYCLE OF B. SIMPLEX

Carefully breaking down with the tweezers all the plants from the "cake". Once they are dried, they will be grind to dust and used to determine the distribution of stable carbon (13C) and nitrogen (15N) isotopes to gain deeper insights about B. simplex plant communities and their ecological niche.

Different shapes and life stages of B. simplex sporophytes found in 1 "cake".

A few years ago, Radvile Rimgaile-Voicik made history by being the first to discover and photograph B. simplex gametophyte in Europe.

Studying gametophytes is particularly intriguing because they are among the least explored botanical phenomena. This lack of research hinders our understanding of their population dynamics, ecological requirements, and interactions with the environment. A systematic investigation into gametophytes may reveal how ancient plants such as B. simplex adapt and thrive in current ecosystems.

Carefully examining the soil once again, searching for the gametophytes. ↓

Another gametophyte ↓ This time together with a sporophyte (which is still undergound) in front of the macro camera. In the gametophyte, sometimes it is possible to see archegonia, which are structures that produce eggs, and antheridia, which produce sperm cells.

What do we see here??? ↓ Triplet emerging from a single gametophyte or intermingled dance of three separate individuals?

In today's culture, the pursuit of value is commonplace. Why is it important to research B. simplex — many would ask. But how would we measure its value? B. simplex is valuable in itself. Sometimes is more worthwhile to investigate the unknown than to merely satisfy current societal demands.

Research on B. simplex remains minimal; we are only scratching the surface. Yet this species is categorized as very rare and critically endangered (Category 1 (E)), requiring conservation efforts to prevent extinction. New ways of engagement and collaboration with humans?

Returning to the tradition of seeking the "fern flower," perhaps it entails attentive observation and dedicated time spent with the plant. From its unique perspective, it may offer learning opportunities — botanical, biological, social, cultural, historical, anthropological, etc. — if only we take the time to engage. Radvile says that from B. simplex we learn to take all the time we need, unhurried and patient.

The enthusiasm for studying Moonworts is contagious, this phenomenon is called Moonwort Madness (also known as Botrychulitis).

By the way, more about the habitat and botanizing adventure for B. simplex was in the last month's observation.

Radvilė Rimgailė-Voicik et al. (2024) Botrychium simplex (Ophioglossaceae) in the Baltic countries and adjacent areas – a monographic study. Nova Hedwigia, Vol. 118 (2024), Issue 1-2, 183–239

Sources