Selaginella - Selaginella

Japanese: イワヒバ - いわひば

An evergreen fern of the Selaginellaceae family. It is also called Iwamatsu. It produces pseudostem made of intertwined roots. The pseudostem rarely branches, and the larger ones can reach over 20 cm in height. Branches grow radially from the tip of the pseudostem. The branches branch several times, and when dry, they roll inward. The leaves on the branches are scale-like, with two rows of ventral leaves on the left and right and two rows of dorsal leaves on the top. The ventral leaves are usually large, 1.5 to 2 mm in size. The sporangium at the tip of the twigs is 5 to 15 mm long and rectangular columnar. It grows on rock walls and rocks in sunny places in mountainous areas, and is resistant to dryness. There are many variations in the shape and color of the branches, and it has been known as a horticultural variety since the Edo period, and there are currently over 150 varieties. Many are displayed as bonsai, but they are also planted in gardens. Those with white spots, yellow spots, and golden leaves are highly valued. Pseudostem is occasionally used for the cultivation of epiphytes. Apart from asexual reproduction by adventitious buds in the wild and reproduction by spores, in horticulture, varieties are maintained and propagated by "leaf cuttings", in which a part of a branch is cut and inserted into sandy soil.

[Harufumi Nishida]

Cultivation method

Put Kanuma soil in the bottom of the pot and then add a mixture of 5 parts leaf mold and 5 parts sphagnum moss, or 4 parts Kanuma soil and 6 parts sphagnum moss on top. The trick is to vary the amount of sunlight depending on the variety; white spotted varieties should be exposed to sunlight for 2 hours in the morning and evening, and yellow spotted varieties should be exposed to sunlight for 3 hours in the morning and evening, with the rest of the time placed under a bamboo blind. Golden yellow varieties should be placed under a bamboo blind for only 3-4 hours during the day, and exposed to sunlight the rest of the time. Water thoroughly from spring to autumn, but in winter put them in a frame or indoors and water just enough to keep the soil from drying out.

The closely related species, S. involvens , does not produce pseudostem, but has shallow underground rhizomes and upright aboveground stems. The aboveground stems are 15-40 cm tall. They branch pinnately several times and have scale-like ventral and dorsal leaves. Sporangia are terminal to the twigs. The leaf blade is yellow-green in color. They grow in colonies on rocks in mountains in various places west of the Kanto region.

[Harufumi Nishida]

Main types of ferns (3) [specimen illustrations]
©Junzo Fujishima ">

Main types of ferns (3) [specimen illustrations]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

Japanese:

イワヒバ科の常緑性シダ。イワマツともいう。根が絡み合ってできた仮茎をつくる。仮茎はまれに分枝し、大きなもので高さ20センチメートルを超す。仮茎の先端には枝が放射状に束生する。枝は数回分枝し、乾くと内側に巻き込む。枝につく葉は鱗片(りんぺん)状で、左右2列の腹葉と上面2列の背葉とがあり、普通は腹葉が大きく、1.5～2ミリメートル。小枝の先端につく胞子嚢穂(ほうしのうすい)は長さ5～15ミリメートルで、四角柱状。各地の山地の岩壁や岩上の日当りのよい場所に着生し、乾燥には強い。枝の形や色などに変異が多く、江戸時代から園芸品種として知られ、現在150に余る品種がある。多くは盆栽として観賞されるが、庭植えされることもある。珍重されるのは、白斑(はくはん)の入ったもの、黄斑の入ったもの、黄金色の葉をもったものなどである。仮茎はまれに着生植物の栽培用に用いられる。野生状態での不定芽による無性生殖や、胞子生殖とは別に、園芸的には枝の一部を切って砂地に挿す「葉挿し」によって、品種の維持、増殖がなされている。

［西田治文］

栽培法

鉢底に鹿沼土(かぬまつち)を入れ、その上に腐葉土5、ミズゴケ5、あるいは鹿沼土4、ミズゴケ6の混合土を入れて栽培する。日照時間は品種によって変えるのがこつで、白斑系は朝夕2時間ずつ、黄斑系は朝夕3時間ずつ日光にあて、あとはよしず張りの下に置く。黄金色系は日中3～4時間だけ、よしず張りの下に置き、あとは日光にさらす。春から秋までは十分に灌水(かんすい)するが、冬はフレーム、または屋内に入れて、鉢土が乾かない程度に水をやる。

　近縁種のカタヒバS. involvensは仮茎をつくらず、浅く地中をはう地下茎と直立する地上茎をもつ。地上茎は高さ15～40センチメートル。数回羽状に分枝し、鱗片状の腹葉と背葉をつける。胞子嚢穂は小枝に頂生する。葉身状の全体は黄緑色。関東地方以西の各地の山地岩上に群生する。

［西田治文］

シダ植物のおもな種類(3)〔標本画〕

出典　小学館　日本大百科全書(ニッポニカ)日本大百科全書(ニッポニカ)について　情報 | 凡例

<<: Iwahibari (Iwahibari) - Iwahibari (English spelling) accentor

>>: Colysis elliptica (Thunb.) Ching