rare species – Not Very Far Away

*Sceptridium rugulosum* (St. Lawrence Grape Fern) in November and turning slightly purple in the colder weather. Unless protected from the cold by leaf litter, the fronds turn a bronzy purple. In the spring, they turn green again.

Grape ferns (Sceptridium) and their relatives, the moonworts (Botrychium), are an odd bunch. They grow from stubby subterranean stems with a few thick roots. The stems produce one leaf, rarely two, a year. That leaf is succulent, divided into two parts, one of which is photosynthetic (trophophore), the other reproductive (sporophore). They have a series of buds, one above the other on the subterranean stem, for the next five or so years of leaves.

The photosynthetic part of the Sceptridium leaf is semi-evergreen, meaning it will survive the winter more or less intact. Then, in the spring, it withers away. For a few months, there is no leaf, and then in early summer, a new leaf slowly uncoils, a process that may take more than two weeks.

Grape ferns get their name from the clusters of globular sporangia on the sporophore that look like little bunches of grapes. Grape ferns and their relatives the moonworts were previously placed together in the genus Botrychium. The genus name Botrychium is from the Greek “botrychos” for “bunch of grapes” and Latin “ium” for “small”. The genus name Sceptridium is from the Greek “skēptron,” meaning “scepter” in reference to the upright sporophore.

Sceptridium rugulosum

Sceptridium rugulosum is a grape fern, one of four species known from Minnesota, and it is one of the two rare ones, the other being Sceptridium oneidense.

Description

Sceptridium rugulosum has a green, 2 to 4 pinnate, 15 by 26 cm trophophore blade with up to nine pinnae pairs. The surface is rugulose (finely wrinkled) and concave. The angular pinnules (secondary segments) have denticulate margins and pointed tips.

Sceptridium rugulosum can live for many years. The one in the photo below was first seen eighteen years ago.

**This *Sceptridium rugulosum* is more than eighteen years old.**

Habitat

Look for Sceptridium rugulosum in brushy fields, open forests, and meadows.

Range

Sceptridium rugulosum is endemic to the Great Lakes and St. Lawrence Seaway regions. The range map above from the FNA is a bit outdated, and Sceptridium rugulosum is now known to occur more widely in Minnesota. There is also a report from Connecticut.

Taxonomy changes

At one time, Sceptridium rugulosum was considered to be a variety or form of Sceptridium (Botrychium) multifidum under the name Botrychium multifidum forma dentatum. It was also included under the name Botyrchium ternatum, which is as an eastern Asian species distinct from Sceptridium rugulosum. Also, the name Botrychium ternatum is listed as auct. non (“of authors, not”), meaning the name was applied by multiple authors to different species.

Sources

Flora of North America: Botrychium
Flora of North America: Botrychium rugulosum
Wagner, W. H., Jr., and F. S. Wagner. 1993. Botrychium. Pages 86-101 in Flora of North America Editorial Committee, editors. Flora of North America north of Mexico. Volume 2. Oxford University Press, New York, New York.
Minnesota DNR Rare Species Guide: Sceptridium rugulosum
Go Botany native plant Trust: Botrychium rugulosum – St. Lawrence grapefern

I saw this *Leucobrephos brephoides* on March 30, 2006. Even though I look for it each spring, I have never seen it again. When I found it, the marsh it was in was beginning to flood, snow and ice were still on the ground, and the air temperature that day was in the mid-30s to low-40s F. This is a hardy moth.

Leucobrephos brephoides is a rare moth species in the family Geometridae, subfamily Archiearinae. I have seen it only once, back in March 2006. Even though I look for it every year in late March and early April, I have not found it again.

The one and only time I have seen it, there was still snow on the ground, although it was melting. In the marsh where it was resting on some grass, a flood was beginning. And it was chilly, in the mid-30s to low-40s F. For Leucobrephos brephoides, this was a normal day.

I was excited to find this little moth. It was cold and there was still snow on the ground. I’d never really thought of insects being active so early. Since then, I have found that many insect species, beetles, moths, wasps, and midges, are active this early. Even spiders are out. Some insects are feeding on nectar and pollen from early-flowering willows. Others are seeking mates. A few, along with the spiders, are hunting other insects.

Description

The forewing of Leucobrephos brephoides is black and dusted with grey. The postmedial line is black with a white border. The antemedial line is also black but lacks a white border. The hindwing is white with an even black margin and basal black scaling.

Males have pectinate (feathery) antennae, the females have filiform (thread-like) antennae.

*Leucobrephos brephoides* on March 30, 2006

Life history

In the spring, female Leucobrephos brephoides lays 1 to 3 eggs on a leaf scar near the tips of aspen branches. They may lay their eggs thirty or more feet from the ground or just a few feet from the ground. After about 15 days, the eggs hatch. The larvae go through five instars before burrowing into the soil and pupating.

In the spring, the adults emerge from their pupa. Adult Leucobrephos brephoides are day fliers and active even while temperatures are still cold and snow is still on the ground.

**Catkins of quaking aspen (*Populus tremuloides*)**

Habitat and host plants

Leucobrephos brephoides inhabits open mixed broadleaf and coniferous forests. Its primary host plant is quaking aspen (Populus tremuloides), but it also feeds on paper birch (Betula papyrifera) and alder (Alnus incana). Larvae have also been found feeding on willow (Salix spp.) and balsam poplar (Populus balsamifera). All of these species produce catkins in the early spring before their leaves emerge. Catkins may be an important food source Leucobrephos brephoides larvae, which hatch from their eggs before leaf emergence.

Leucobrephos brephoides is found in cool northern forests where its primary host plant, quaking aspen, grows.

What do the adult moths eat?

Gibson and Criddle (1916) made some interesting observations about the food preferences of the adult Leucobrephos brephoides. They found that sugar baits did not interest the moths. Instead, they noted that rotten meat was attractive. The moths also sought moisture and could be found on muddy roadways near aspen woods.

Similar species

A similar species, also active when Leucobrephos brephoides is in flight, is Archiearis infans. Archiearis infans is more common and widespread than Leucobrephos brephoides. It has bright orange underwings. I’ve seen this species one time also, and that was in the spring (April 2021) during the day at a mud puddle. It lays its eggs in the spring, and the larvae feed on the same plants as Leucobrephos brephoides.

Other Leucobrephos species

Leucobrephos is a Holarctic genus with two species: Leucobrephos brephoides in the Nearctic and Leucobrephos middendorfii in the Palearctic. Leucobrephos middendorfii occurs in Siberia, Mongolia, and the Ural Mountains. The species Leucobrephos mongolicum is considered a synonym of Leucobrephos middendorfii, as is Leucobrephos middendorfii ussuriensis. The subspecies Leucobrephos middendorfii nivea is considered valid. Host plants of Leucobrephos middendorfii are from the same genera as those of Leucobrephos brephoides.

Range of Leucobrephos brephoides

**The *Leucobrephos brephoides* range map shows a wide range but few records.**

Next year

Next March and April, I’ll be out looking for Leucobrephos brephoides again. I’ll check the edges of the woods and marsh for moths, as I have in previous years. I’ll also check the aspen and willows for eggs and larvae. I’m also going to set out bait stations, some with sugar to mimic sap and others with spoiled meat. Maybe after twenty years, I will finally see this scarce moth again. Or maybe not. It is possible that since 2006, the climate here has gotten too warm for this cold-loving species.