Per offrirti il miglior servizio possibile RareAquaticPlants utilizza cookies. Continuando la navigazione nel sito autorizzi l’uso dei cookies |Maggiori Informazioni

RAP Forum

RAP Shop
Collaboratori di RAP
English Articles
Siti Amici
Schede Piante
Articoli Tecnici
Tecniche Riproduzione
Foto Piante
RAP Algae
Coltivazione Emersa
Layout & Manutenzione
Allevamento Caridine
YouTube Channel
Le News

Share on Facebook

I thank Mr. Giovanni Bubici a lot for his productive and important translation work, that has maintained the original content and descriptions of the italian version of this article

Family: Probably Xyris angustifolia
Synonyms: Eriocaulon sp. 'Japan' - Eriocaulon sp. from Japan - Eriocaulon sp. 'Narrow Leaf' - Eriocaulon sp. 'Narrow Leaf'

Unknown - probably Japan

Plant structure:

Rhizome – equitant leaf arrangement

Difficulty Difficult
Light Requirement:

Medium-High (>0.7 W/L)


Fertilized substrate; ADA, Amazonia I, II, Malaya; Dennerle, Deponit, èquo Eden, Elos, Akadama, allophane soil, etc.

Grow rate: Slow
Emerged growth: Unknow

It is a species unidentified yet. Very likely, it is one of the biggest Eriocaulon sp. known so far (ndr)


Iannella Massimo’s preface on the nomenclature

This rare species was obtained about six months ago, and as of now the sole two samples in Europe have been originated from some mother plants of mine. Currently, it has the inappropriate name Eriocaulon sp. 'from Japan', which alas refers to other Eriocaulon spp. known from aquarists worldwide. I could not get further information on this species from the seller and websites. Other species, largely known from the international aquarist community, are Eriocaulon sp. 'Japan', Eriocaulon sp. 'Japan Type I', and Eriocaulon sp. 'Japan Type II' or Eriocaulon sp. from 'Japan', and others, which differ in a few characteristics. The species described here was provided to me as an Eriocaulon sp. 'from Japan', but I have believed useful to give it a more appropriate name in order to emphasize its peculiarities for distinguishing it from the others. For this reason, I propose the nameEriocaulon sp. 'Japan Needle Leaf', so that to highlight the trait of very narrow and long leaves, and the geographical origin.

I want to underline that this ‘pseudo-nomenclature’ is merely arbitrary, and it has not any taxonomic value at all.

The plant sample as obtained




Just for example, here are two pictures of Eriocaulon sp. 'Japan', completely different, though with the same name. They are of different growers/sellers. Actually, there are other plants with the same name and a rosette growth habit.

Eriocaulon sp. 'Japan'


Eriocaulon sp. 'Japan' from aquacharming


The confusion of the species

Due to deep searches and observations, I have ascertained that Eriocaulon sp. 'Japan Needle Leaf' is a species different from:

- Mesanthemum sp. 'Africa'

- Eriocaulon sp. 'Africa'

- Eriocaulon lividum

Moreover, it should be noted that Eriocaulon sp. 'Africa' is very likely a synonym of Mesanthemum sp. 'Africa', though the certainty is still lacking.

Eriocaulon sp. 'Africa' aka Mesanthemum sp. 'Africa'


Eriocaulon lividum


Botanical description

It should be noted that my observations are not a botanical description with a scientific value, but just details to be used to recognize the species.

Plant probably perennial, with a rhizome variable in length, creeping, horizontal bearing, green color, section diameter of 0.4-0.8 mm, white inner tissues, very short internodes particularly evident in the older parts, leaves equitant, opposite, very close together forming a dense tissue, sheath wide at the base and enveloping the rhizome almost completely, white in color, partially covered by the sheath of older leaf. Leaves parallel-veined, with variable length up to 50 cm, filiform blade wider at the base, 0.4-0.8 mm wide, rigid in the 10 cm-proximal part, very narrow (0.1-0.2 mm wide) at the apex, fluctuant, acuminate apex, entire margin, tissues very fibrous, coriaceous, hard to cut with blades or scissors. Fibrous roots originating from rhizome and leaf’s base, long up to 30 cm, fibrous and hard to cut, numerous, they anchor firmly to the substrate, and extend considerably. Inflorescence is still unknown.

The leaves


The root system


The rhizome




-Shoot budding

Shoot budding (as in the picture) starts with the detachment of a young leaf blade, which initially shows an appearance curly with several loops. The young shoot possesses several leaves that slowly straighten up to take the typical morphology. This surprising expression makes this species really spectacular.









General description

This rare Eriocaulon sp. is probably the biggest aquarium-grown plant species. In fact, leaves are long up to 50 cm, almost completely fluctuant, rigid and spectacularly geometric in the 10 cm-proximal part, morphologically similar to a little palm (such as Eichhornia azurea). It is a big plant with a moderate to slow growth rate, adequate for the center aquarium zone (not necessarily in the background) also in middle-size aquariums, because the leaves, very narrow, do not block the view and produce a very limited shadow.

This is an unusual and surprising species, which possesses interesting characteristics, and, due to its rare morphology, represent a real novelty in the worldwide aquarium scenario.


Among Eriocaulon spp., this is one of the easiest to grow species, though the particular requirements for its good growth might make it not so easy to growth for beginners. Nevertheless, cultivation may have different aims: to grow the plant in order to obtain a normal growth (growth somewhat slow) is quite easy, but to propagate the plant is difficult.

I have grown this species only in a soft water, and I believe this should be adequate for this species, as widely recommended for the other species within the genus. Optimal conditions are kH 0-4, gH 2-5, pH 6-7, and temperature of 22-28°C. Very likely, as for Eriocaulon sp. ‘Goias’, this species can grow under several conditions. The substrate is very important for the propagation: the species prefers organic, clayey, acid substrates, such as Amazonia I, II and Malaya, while shows a slow and stunt growth in poorly fertilized substrates. It is not recommended to growth this species in quartz or inert materials, even with fertilizing tabs. Its robust roots suggest that nutrients uptake occurs mainly through the roots rather than the foliage, as for the other Eriocaulon spp.. Pictures show the vigorous root system even on a plantlet. I want to highlightthat I have obtained the highest growth rate and final development by using ADA Aqua Soil Amazonia I. Intense light (about 0.7 W/L) promotes growth and lateral shoot emission. I grow this species in tanks provided with PL lamps with 4000-8000°K or T5 neon with 6700°K, and the latter allow to obtain a better growth and a higher production of adventitious plantlets. A lower light intensity slows down the plant growth, causes a lower leaves emission, though with no particular problems for the plant. Fertilization is important, but lesser than for other more exigent Eriocaulon spp.. This species is not sensitive to iron chlorosis, and maintains the leaf green color even with low iron concentrations. This advocates again the importance of fertilized substrates. I have carried out trials with several fertilizers such èquo, ADA, Elos, Seachem, and mixtures of K-, N- and P-salts. CO2 should be supplied because it contributes to reduce the water pH, as preferred by this species, thus promoting a faster growth. Optimal CO2 concentrations are 20-25 ppm. Under optimal conditions, the plant shows pearling and a deep white color of the insertion point of leaves on the rhizome (typical trait of the species shown in the pictures).

Agamic propagation

As I have largely described for Eriocaulon sp. ‘Gioias’, adventitious plant emission in this species can be stimulated by several methods. One method consists in cutting the rhizome with a sharp scalpel, taking care to put the scalpel blade between two leaves. For this purpose, the plant has to be eradicated from the substrate, placed on a rigid surface, and energetically cut; in fact, the plant has tissues compact and hard, almost ligneous. Due to the high force, scalpel blade could skew, and the cut could be not clean, thus damaging the meristems, which are useful for the plant propagation. Here below, I report some details of this technique, largely described by myself as ‘tecnica dei tagli a cuneo’ (wedge cuts technique), in order to improve its outcome:

- the cut must be made vertically, viz. rhizome axis and scalpel blade must form a 90° angle

- the cut must not be made by halving the rhizome, as for the other Eriocaulon spp.; in this case, the rhizome may be subdivided into several parts, taking care that each of them is provided with roots and at least two leaves

- the apical rhizome part will start to grow soon, because it has the apical meristem, but seldom will produce lateral shoots

- the basal rhizome parts very probably will produce lateral shoots, but this needs a long time

- the rhizome parts should not be incorporated completely in the substrate, and a great part of them should remain exposed to the light in order to allow orientation and differentiation of the cells (tropism).




Basal rhizome part


Apical rhizome part



- Propagation stimulation by other methods

Besides the above described method, which is very invasive and risky because can cause the plant death, adventitious plantlets formation can be stimulated by other methods:

- temperature excursion from 25-26°C to 20°C for 4-7 days

- placement of fertilizing tabs (I use ADA Iron and Multi Bottom) periodically at the plant base

- intense light

- uplift of the rhizome to allow its creeping growth above the substrate