Familia: Hylocomiaceae ⇾Genus: Rhytidiadelphus • goose neck moss ⇾Species: Rhytidiadelphus triquetrus – rough goose neck moss
|Genus name: Rhytidiadelphus • フサゴケ属• fusa goke|
The name Rhytidiadelphus is based on two Greek words: the Greek rhytis, meaning wrinkle and the Greek adelphos, meaning brother. There is another moss named Rhytidium: some people think Rhytidiadelphus means brother of Rhytidium, and others say Rhytidiadelphus means wrinkled brother, or wrinkled brotherhood.
About genus: Rhytidiadelphus, goose neck or “feather mosses,” are large (about 10 cm) robust mosses, in which the shoots are erect to lying along the ground (procumbent.) The stems are usually long and irregularly branched, resembling a feather. The leaves are broad at the base, gradually or abruptly narrowing to a sharply pointed tip; each leaf may have a short double nerve, or it may be nerveless. The seta (capsule’s stalk) is deep red and smooth.
The genus contains 4-5 Species (+ several variations) – their world distribution:
• Rhytidiadelphus triquetrus (rough goose neck moss) – is known to occur in Northern
Hemisphere, but also Eurasia (Europe & Asia) and New Zealand.
• Rhytidiadelphus loreus (goose neck or lanky moss) – North America, Europe and some
• Rhytidiadelphus squarrosus (square goose neck moss) – North America, Eurasia, New
Zealand and Tasmania, plus some Atlantic Islands
• Rhytidiadelphus subpinnatus — North America and Eurasia
• Rhytidiadelphus japonicum (Japanese goose neck moss) – occurs on all 4 big islands in
Japan, as well as on the Aleutian Islands.
Species description: Rhytidiadelphus triquetrus is also knows as rough goose neck moss, bigshaggy moss, and because of its fuzzy appearance and tail-like shape it is also called the ‘electrified cat’s tail moss’.
オウフサゴケ • the genus name is fusa goke. The species name is the same except for the first two characters, which are Romanized as ‘o-u’, meaning ‘large’ fuss goke. It grows on Hokkaido, Honshu, Shikoku.
The Latin species name refers to the triangular shape of the leaves and the occasional three-rowed arrangement of the uppermost leaves of some stems.
Rhytidiadelphus triquetrus is a bushy, shaggy moss with long, branching shoots giving it somewhat untidy appearance. The branch leaves have two weak veins extending to over half of the length. The drawn-out tip is toothed.
It has a pleurocarpous (spreading) growth and forms pale yellow-green, loose mats of coarse, interwoven, sub-erect, branched shoots in which the strongly divergent leaves form bristly shoot tips. The stem is red, while the leaves are yellow-green in color. Sporophytes are red-brown when mature and maturation typically occurs in the spring.
Habitat: rough goose neck moss usually grows in well-drained sites in coniferous forests, on cliff shelves and over boulders and logs; occasionally epiphytic on tree trunks. It grows terrestrially on humus-rich substrates and is less common in lowland rainforests. It is often the dominating moss species in moderately rich forest habitats in the boreal regions and the PNW.
Distribution: Rhytidiadelphus triquetrus is known to occur mostly in Northern Hemisphere (north America and Europe), but also some places in Asia and New Zealand.
In North America across the boreal portion of Canada and Alaska, southward in the east in mountains to the southern Appalachians and Arkansas, in the west to California.
In Washington State, there are four species of Rhytidiadelphus: Rhytidiadelphus triquetrus, Rhytidiadelphus loreus, Rhytidiadelphus squarrosus and Rhytidiadelphus subpinnatus.
R. triquetrus vs R. squarrosus: (we have both of those mosses in our garden, mostly in W) R. triquetrus is often conspicuous, with tall, tough, erect stems from which branches arise irregularly to give a bushy habit; the leaves are large and spreading, and capsules are rarely formed. It is found mostly in woodland clearings. R. squarrosus is a smaller moss with rough/scaly (squarrose) leaves; the shoot top tips have a characteristic star-like appearance. It is found in moist grassland and is a common weed in lawns.
Rhytidiadelphus triquetrus mostly grows on the west side of the Tea House Garden (Area W):
1.) It forms a robust irregular large (2-3 m diameter) lush mat, rather loosely woven, behind Machiai, but often ‘jumps’ on top of the neighboring colony of Polytrichum commune (prized cryptomeria/sugi moss), from which is continuously weeded out, so it does not choke it.
2.) In roji proper, also on the west side, between stepping-stones and the fence – it forms longish and much more dense mat of very shaggy and carpet-like appearance. Unlike the path behind Machiai, this mat is strongly attached to soil.
So far it was not found in any other parts of the garden.
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Polish species name of Rhytidiadelphus triquetrus is fałdownik trzyrzędowy (listed as under partial protection plant in Poland* – see link below)
References and related reading:
* – Rhytidiadelphus triquetrus was under protection in Poland in 200-2004, but not on a current protection list.
• Nice entry on the R. triquetrus from University of British Colombia blog
• Clear macro photos of the plant from Pbase (crowd-sourced photo galleries)
• Up-close pic of R. triquetrus moss + a drawing of typical leaf with 2 costas (veins) and toothed tip from Mosses & Liverworts of the Outer Hebrides (UK)
• This research paper from New Zealand describes HYLOCOMIACEAE family there, including Rhytidiadelphus genus (2 species). Rhytidiadelphus triquetrus grows only in one locality in New Zealand (St Arnaud), but it’s invasive and managed/eradicated by raking and burning the larger colonies in order to preserve existing montane forest ecosystem.
Literary reference – a moss tourist note:
‘The Magical World of Moss Gardening’ by Annie Martin has a chapter (page 44) about the Bloedel Reserve on Bainbridge Island, WA. Part of this 150-acre woodland reserve is designed as the moss garden, which is considered the largest in North America with more than 40 species of bryophytes that thrive in PNW climate. The author writes that ‘R. triquetrus adorn weathered tree stumps’ and points out where to look for other mosses. So, if you are visiting Seattle Japanese Garden in person, maybe you can hop on a ferry from downtown Seattle to Bainbridge Island and visit Bloedel Reserve – it’s about 7 miles from the ferry dock terminal on the other side of the water, and besides having the moss garden part it also contains the Japanese Garden part.