Psilotum nudum
Plant Family
Psilotaceae
Binomial Name
Psilotum nudum (L.) Palisot de Beauvois.
Note: the name of the genus is from the Greek word psilos, meaning smooth or naked. The specific name nudum is from the Latin word nudus, also meaning naked.
Synonymous Binomial Names
Bernhardia dichotoma, Lycopodium nudum, Psilotum nudum var. oahuense, Psilotum nudum var. normale, Psilotum oahuensis, Psilotum triquetrum
Common (Vernacular) Names
Cocks crow, forest moa, skeleton fork fern, whisk fern, whiskbroom fern, upright whisk fern, naked fern. Hawaiian names: moa, moa nehele, oo moa, pipi. Japanese Matsubaran (pine needle)
Plant Characteristics
Endemicity. This species is widely distributed across tropical and subtropical areas of the Americas, Africa, Asia and Australasia, with a small, endangered population found in southern Spain (OU 2020). Small populations extend into the subtropical areas of Florida, North Carolina the other southern states. It is indigenous to all of the major Hawaiian islands, Midway Atoll (Starr, Starr and Loope 2006) and the smaller Northwest Islands of the archipelago.
The other species in the genus, Psilotum complanatum, readily hybridizes with Psilotum nudum to form the hybrid Psilotum x intermedium (OU 2020). Psilotum complanatum is also indigenous to the Hawaiian Islands. Hybrids of the two species are an infrequent to locally common plant found in mesic to wet forests, from 1640 to about 2790 feet, on Kauaʻi, Oʻahu (particularly in the Waiʻanae Mountains), Lānaʻi, and Maui (UH 2009).
Growth Habit. This fern has two distinct life cycle phases: a rhizome-like gametophyte generation that lives underground and is nourished by endomycorrhizal fungi (Winther and Friedman 2009), and the dominant sporophyte generation that is above ground and carries out photosynthesis. Psilotum species are the only living vascular plants to lack both leaves and roots. Moisture and minerals are absorbed through hair-like rhizoids into a basal rhizome. Its distinctive dichotomously branching, triangular stems are solely responsible for photosynthesis and gas exchange. In place of leaves, the stems bear minute scales (enations) that lack vasculature (OU 2020).
Moa is evergreen, long lived and generally has an upright habit reaching a maximum height of about 50 cm. It grows in soil, on rocks (a lithophyte) or on other plants (an epiphyte). The stems range from dark green to yellow or yellowish orange depending on the light exposure and habitat conditions. Plants grown in moist shady areas are usually medium to dark green.
 Psilotum nudum Epiphytic on Philodendron spp. |
Reproductive Bodies. In Psilotum the reproductive bodies bearing the spores are referred to as synangia (synangium singular). They are spherical, yellow and borne in the axils of enations on the upper parts of the aerial shoots. The synangium consists of three chambers or locules, a fusion product of three sporangia. The wall of the synangium is 3-4 layered with a thick outer wall forming the epidermis and an inner wall separating the three locules. When the synangium is ripe it splits along three longitudinal lines of dehiscence on the locules releasing spores.
 Ripening Synangia of Psilotum nudum |
 Psilotum nudum Macro Photo of Synangium |
 Psilotum nudum with Empty Synangium |
Spores. Each locule is filled with large number of bean-shaped, microscopic spores that are homosporous (not differentiated by sex). They grow into bisexual gametophytes (producing both male and female gametes).
Conservation Status
This species is not considered endangered or threatened.
CITES Listing: Psilotum nudum does not appear on any Appendices of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES 2020).
IUCN Listing: Psilotum nudum is not listed on the Red List (IUCN 2020).
Endangered Species: Psilotum nudum was not found on the U.S. Fish and Wildlife Service’s Endangered Species Database (FWS 2020).
Uses
Landscaping. Moa is used as an accent ornamental and ground cover and looks nice on and among lava rocks. It is also a great bonsai container plant and can be grown indoors. The plants spread easily by spores often resulting in the spontaneous appearance of plants in greenhouses and plant collections.
Leis. Moa was used in lei making by the early Hawaiians and continues to be used in leis for people and horses [Neal, cited in UH 2009].
Floral Arrangements. The stems of the plant can be used in floral arrangements and have a vase life of one to two weeks [Neal, cited in UH 2009].
Children’s Game – Moa Nahele “Chicken Vegetation”. Pieces of the plant were used in a game where opposing children holding interlocking branches of the plant pulled them apart until one branch broke. The child with the unbroken branch was the winner and proclaimed victory by crowing like a moa (rooster). [Referenced cited in UH 2009].
Traditional Hawaiian Medicinal Uses. Moa was used as a laxative and in combination with other plants to treat various respiratory conditions and tuberculosis. Its spores were used for diarrhea in infants and like talcum powder for drying and to prevent chaffing [See cross references cited in UH (2009)].
Potential Source of Antibiotic Compounds. In one study extracts from this species showed activity against pathogenic bacteria and fungi suggesting that it could be a good source of antimicrobial compounds. The authors of the study suggested that these compounds may be more effective because the target organisms may be less likely to develop resistant mutants to natural compounds (Rani, Khare and Dantu 2010).
Compounds Present. The chemical diversity of Psilotum nudum has been characterized (Šamec et al. 2019).
 Potted Hawaiian Moa as a Bonsai Subject |
Cultivation
Moa is slow growing but highly adaptable, suitable for lighting conditions ranging from shade to full sun. It can be grown in all well drained soil types with a slightly acidic to neutral pH – organic, and inorganic soils types such as coral and volcanic cinders, on rocks; and both wet and arid habitats. It is not adversely affected by wind and high heat but has low salt tolerance (CTAHR No date).
The article in Hawaiian Horticulture (HIHort 2012) is recommended as a comprehensive reference on this species and its cultivation
Propagation
Spores. The plant is difficult to intentionally grow from spores.
Divisions: Psilotum nudum is usually propagated from divisions of rhizomes.
Improved Cultivars
This was a popular pot plant in Japan during the Edo period leading to the development of many different cultivated varieties with evocative names such as ‘Flying Cloud Pavilion’. Dozens of these varieties are illustrated in the Matsubaran fu, a list of cultivars published by Chōseisha Shujin in 1836 and 1837 (OU 2020). Refer to David Morrison’s incredible blog (Morison 2020) for history and information on these publications, access to images of the original drawings and color photos of the many named Japanese varieties of this plant. The cultivar ‘Bunryu Zan’ was introduced into the US from Japan during the 1950s. A description and photograph is available (Husby 2006).
Pests and Diseases
No commonly encountered pests and diseases have been reported. Root mealybugs may sometimes be found on the stems below ground and rhizomes but do not appear to significantly impact growth. The plants are not attacked by invasive slugs and snails that are major agricultural pests in our area.
Invasiveness Potential
Moa can become weedy in landscaping but does not overgrow other plants. It is not listed as an invasive species:
Global Invasive Species Database. This species was not found on a search of the database (GISD 2020).
CAB International Invasive Species Compendium. No records indicating that this an invasive species were found on a search of the database (CABI 2020).
Toxicity and Precautions
No references indicating toxicity or special precautions in handling this species were found.
Plants and Seeds for Sale
Availability
Plants of this species are seldom available in commerce, perhaps because they are so slow growing that they not cost effective to produce. Our plants were collected on our property where they are fairly abundant, divided into separate rhizomes and container grown.
Spores. Our plants are currently producing very limited amounts of spores and these will be used for our research purposes. Spores may be offered at a future date.
Nursery Stock. A small inventory of non-certified, Hawaiian-grown plants will be offered as an experimental product from our online store beginning in September 2020. As non-certified plants they cannot be shipped to the states of Arizona, California, Louisiana and Texas. It is uncertain if these can be shipped without soil as required by regulations and remain viable. The plants should be planted in a moist, well-draining soil mixture upon receipt. Apply light feedings of a dilute fertilizer monthly or use a slow release fertilizer. Don’t attempt to speed growth by adding more fertilizer. Moa grown in containers tends to maintain its size in proportion to the pot size. Repotting is not needed.
We would like to offer certified plants shipped in artificial media. This will require production of plants from spores in artificial, nematode-free soil media, which is likely to be a slow and problematic process. We are beginning research on this and it is unlikely that certified plants will be available until 2023 or later.
Improved Cultivars
We do not offer improved cultivars of this species. These plants are are grown from wild ecotypes endemic to our area of Hawaii Island.
Shipping Information
Hawaiian moa will be inspected with the rhizomes free of soil and then packaged with in moist paper towels before shipment. The plants are small, light-weight and will be shipped via Priority Mail.
References
CABI (CAB International). 2020. Invasive Species Compendium. https://www.cabi.org/isc/search/index?q=Psilotum [Accessed 26 September 2020].
CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora). Appendices I, II, and III valid from 28 August 2020. https://www.cites.org/eng/app/appendices.php [Accessed 26 Month 2020].
Christenhusz et al. (2011) A linear sequence of extant families and genera of lycophytes and ferns. Phytotaxa 19: 7-54.
CTAHR (College of Tropical Agriculture and Human Resources). No date. Growing Plants for Hawaiian Lei” by CTAHR (College of Tropical Agriculture and Human Resources), University of Hawaiʻi at Mānoa, pages 32, 33. Cited in UH 2009.
FWS (U.S. Fish and Wildlife Service). 2020. Endangered Species Home. Search Endangered Species Database. https://www.fws.gov/endangered/ [Accessed 26 September 2020].
GISD.(Global Invasive Species Database) 2020. http://www.iucngisd.org/gisd/search.php [Accessed 26 September 2020].
HIHort (Hawaii Horticulture) 2012. The Native Fern Than May Not Be A Fern. Hawaii Horticulture. A blog about gardening and plants in Hawaii. http://hihort.blogspot.com/2012/09/the-native-fern-that-may-not-be-fern-moa.html [Accessed 26 September 2020].
Husby C. 2006. Psilotum nudum ‘Bunryu Zan’ https://www.flickr.com/photos/calamites/4569507417 [Accessed 26 September 2020].
IUCN (International Union for Conservation of Nature). 2018. Version 2018-1. The IUCN Red List of Threatened Species™. http://www.iucnredlist.org/search [accessed ## Month 2018].
Morrison D. 2020. Psilotum (Matsubaran). https://primitiveferns.blogspot.com/p/matsubaran-fu-1836-woodblock-water.html [Accessed 26 September 2020].
Rani, D., Khare, P. B., & Dantu, P. K. (2010). In Vitro Antibacterial and Antifungal Properties of Aqueous and Non-Aqueous Frond Extracts of Psilotum nudum, Nephrolepis biserrata and Nephrolepis cordifolia. Indian journal of pharmaceutical sciences, 72(6), 818–822. https://doi.org/10.4103/0250-474X.84606
Šamec, D., Pierz, V., Srividya, N., Wüst, M., & Lange, B. M. (2019). Assessing Chemical Diversity in Psilotum nudum (L.) Beauv., a Pantropical Whisk Fern That Has Lost Many of Its Fern-Like Characters. Frontiers in plant science, 10, 868. https://doi.org/10.3389/fpls.2019.00868
Starr F, Starr K, Loope L. 2006. Annotated Checklist of the Vascular Plants on Midway Atoll, Hawaii. https://ecos.fws.gov/ServCat/DownloadFile/147500?Reference=98524 [Accessed 26 September 2020].
UH (University of Hawai’i). 2009. Psilotum nudum. Native Plants Hawaii. http://www.nativeplants.hawaii.edu/plant/view/Psilotum_nudum [Accessed 26 September 2020].
UO (University of Oxford) 2020. Psilotum nudum (L.) P.Beauv. (Psilotaceae). Oxford Plants 400. https://herbaria.plants.ox.ac.uk/bol/plants400/Profiles/OP/Psilotum [Accessed 26 September 2020]
Winther, J. L., & Friedman, W. E. (2009). Phylogenetic affinity of arbuscular mycorrhizal symbionts in Psilotum nudum. Journal of plant research, 122(5), 485–496. https://doi.org/10.1007/s10265-009-0234-8
Wunderlin, R. P., B. F. Hansen, A. R. Franck, and F. B. Essig. 2020. Atlas of Florida Plants (http://florida.plantatlas.usf.edu/). [S. M. Landry and K. N. Campbell (application development), USF Water Institute.] Institute for Systematic Botany, University of South Florida, Tampa. https://florida.plantatlas.usf.edu/plant.aspx?id=2108 [Accessed 26 September 2020]
Page last updated September 26, 2020.