Some similarities to : Interrupted Clubmoss but that has short intermittent narrowings down to bare stem where the narrow leaflets do not grow. Fir Clubmoss grows in similar places on mountains, but lacks the long thin white hairs on the end of each leaf, and is also much longer, sprawling up to a metre in length.

There are only three Clubmosses belonging to the Lycopodium Genus in the UK, Interrupted Clubmoss (Lycopodium annotinum) which is found extensively in the northern part of Scotland Inverness northwards, Arctic Stag's-horn Clubmoss (Lycopodium lagopus) which is found in only one hectad in Scotland, and this one which is found in the heaths, moors and mountains of Endland, Wales and Scotland, although may have all but disappeared from Ireland with only one hectad remaining in the decade 2000 - 2009.

But there are Clubmosses belonging to other Genera, namely Selaginella, Diphasiastrum, and Huperzia (the latter belonging to a differing family, Huperziaceae.

Stag's-horn Clubmoss (aka Common Clubmoss in the USA) is toxic. The spores of this clubmoss are not known to be toxic, but have in the past been used as a dusting agent on latex condoms where asthma of a few workers employed to deploy the dust has been reported.

There are about 200 alkaloids within Stag's-horn Clubmoss belonging to about 20 skeletal types. Together they amount to 0.2% by mass, by far the most abundant at 84.4% (of the solvent extraction) is Lycopodine which is poisonous, followed to a much lesser extent by Clavatine which is toxic (but may just be a name for the tincture obtained from the plant rather than a specific molecule in its own right, since your Author has failed to find any structural formula for this), and Lycovatine A. Those alkaloids with the Lycopodine skeleton are by far the largest group, the next most abundant skeletal types being the Lycodine type, followed by the Annotine skeletal group and finally the Selagine skeletal group. Those last four are the main skeletal types, but there are another 16. Some of the rest of these skeletal forms can be found on the page for Fir Clubmoss.

It also contains polyphenolic acids such as Dihydrocaffeic Acid and flavonoids such as Apigenin.

The cones are long-stalked (apart from the specimens in the far North of the UK where they are un-stalked) and at the top part of forked growths. The spores are ripe July to August.

Habitat is heaths, moors and mountains on acid or alkaline soils mostly in grassy places. It formerly grew throughout the UK, but is now absent from most lowlands. It is Native.

The toxic spores were once collected as a fine yellow powder called 'Lycopodium' powder and used in classroom science demonstrations, where sound vibrations on brass plates are made visible or the presence of electrostatic charges easily betrayed. They are highly inflammable and were once used in fireworks where they burn explosively emitting sparks and in photographic flash powders. Their lightness and propensity to stick to any slight electrical charge or oil also made it useful as a fingerprint powder. The spores have also been used to treat skin disorders and as a tonic in traditional Chinese medicine.

The stems have been used in matting, and to yield a mordant for dying. The extract of the plant also been used herbally to for nervous conditions, bronchitis, pneumonia, and almost anything, but more recent investigations reveal that the extracts show anti-inflammatory, anti-microbial, anti-fungal, anti-viral, hepatoprotective and anti-cancer properties, with Lycopodine being the main alkaloid. Collectively, the alkaloids within Clubmosses are a moderately hazardous neurotoxin, causing vomiting, nausea, dizziness, staggering and coma. It can be lethal.

LYCOPODIUM ALKALOIDS Many mosses belonging to the Lycopodium, Huperzia and Phyloglossum Genus [all three belonging to the Lycopodiaceae Family] contain highly toxic quinolizidine alkaloids such as Lycopodine, annotidine aka Annotinine, Huperzine A and Selagine. Huperzine A and selagine have similar structures and are found in a wide variety of Clubmosses. There exist many other variations on this molecule.

'CLAVATINE' Clavatine, (aka Claviformine, Expansine, Leucopine, Mycoine, Penicidine, and Tercine but now known only as Patuline) does not contain nitrogen and is therefore not an alkaloid. It is however, a lactone. It was first found in numerous species of Aspergillus and Penicillium moulds, especially Penicillium Expansum, Penicillium Claviform and Aspergillus Clavatus. It has more recently been found in Penicillium Patulum, hence the new name Patuline, all previous names being now dis-used. It is a mycotoxin. There seems to be confusing evidence as to whether the Clavatine that is reported to be found in Stag's-horn Clubmoss, which co-incidentally?? has the scientific name of Lycopodium clavatum is identical to the Clavatine to be found in fungal moulds. The alkaloid 'Clavatine' in relation to Clubmosses crops up time and time again on the internet, but no structural formulae is ever forthcoming. It seems more likely that 'Clavatine' is the common name of the extract from Stagshorn Clubmoss and therefore not a single compound at all but rather the old name for a mixture of them. Thus the 'Clavatine' found within fungal moulds and depicted here is not a component of Clubmosses. This confusion has now been halted by a change of name of the fungal compound from Clavatine to that of Patuline.