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Cycas micronesica

May 11, 2024

Cycas micronesica is a species of cycad found on the island of Yap in Micronesia, the Marianas islands of Guam and Rota, and The Republic of Palau. It is commonly known as federico nut or fadang in Chamorro. The species, previously lumped with Cycas rumphii and Cycas circinalis, was described in 1994 by Ken Hill.[2] Paleoecological studies have determined that C. micronesica has been present on the island of Guam for about 9,000 years.[3] It is linked with Lytico-Bodig disease, a condition similar to amyotrophic lateral sclerosis (ALS), due to the neurotoxin BMAA found in its seeds, which were a traditional food source on Guam until the 1960s.[4] The neurotoxin is present due to its symbiosis with cyanobacteria.[5][6]

Cycas micronesica
Scientific classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Gymnospermae
Division: Cycadophyta
Class: Cycadopsida
Order: Cycadales
Family: Cycadaceae
Genus: Cycas
Species:
C. micronesica
Binomial name
Cycas micronesica
K.D. Hill, 1994

Description edit

Cycas micronesica is a medium-sized tree most commonly 2–5 meters tall but can reach heights up to 15 meters. The tree has a straight palm like trunk ringed with frond scars.[7]

Leaves edit

Leaves are 140–180 cm long, flat in section (opposing pinnae inserted at 180 degrees on rhachis), with 130 -150 pinnae, terminated by a spine c. 4mm long; petiole usually glabrous, usually unarmed, rarely spinescent for up to 20% of length, 35 – 45 cm long; median pinnae at 70-80 degrees to rachis, 240 – 280 mm long, 16 –17 mm wide, 0.35 - 0.45 mm thick, glabrous, dull green or slightly bluish-green when developing, becoming glossy mid-green at maturity, flat in section with slightly recurved margins, strongly discolorous, decurrent for 7–10 mm, narrowed to 5.0-6.0 mm at base, 17 – 20 mm apart on rhachis apex attenuate; midrib not sharply raised, more or less equally prominent above and below, 1.2 -1.5 mm wide.[8]

Reproductive organs edit

Like all cycads, Cycas micronesica are dioecious. Females possess clusters of ovules situated on modified leaves called megasporophylls. Male reproductive structures consist of modified leaves called microsporophylls, but each modified leaf has small, compact pollen sacks attached to their lower surface.[9] There has been documentation of the symbiotic relationship the Guamanian C. micronesica with Anatrachyntis sp., which depends on male cones (microsporangia) for oviposition and recruitment in return for pollinating the species.

The microsporangiate cones are pale fawn to pale orange-brown, narrowly ovoid, 30–50 cm long, 8–10 cm in diameter. Microsporophyll lamina are 35–45 mm long, 20–25 mm wide; fertile zone 25–35 mm long; sterile apex 7–10 mm long, not recurved, apical spine somewhat reduced, broad, sharply upturned, 2 mm long. Megasporophylls 27–33 cm long, grey- and orange-tomentose, with 2-6 ovules, lamina 45–55 mm wide, broadly ovate to elliptical, regularly dentate with 16-20 lateral spines, apical spine 8–15 mm long, lateral spines 2–6 mm long. Seeds flatten to ovoid, green becoming orange, not pruinose, 50–60 mm long, 45–50 mm in diameter; sarcotesta 3–6 mm thick.[8]

Conservation edit

Cycas micronesica is threatened by a combination of introduced species throughout the islands of Guam and Rota. The most notable pest is the diaspidid scale Aulacaspis yasumatsui, which was first recognized in Guam in December 2003.[10] Other threats include cycad blue butterfly (Luthrodes pandava), the longhorn beetle (Acalolepta marianarum) which causes stem damage, the alien invasive snail Satsuma mercatoria which feeds on young leaflets, and habitat loss due to the growing human population.[1] Prior to the invasion of Aulacaspis yasumatsui, it was one of the most abundant plants in Guam's forests.[11] Plant mortality was so rapid that the species was Red Listed as Endangered in 2006, only three years after the devastating invasions began.[12][13] Population counts in northwest Guam have declined from 686 individuals in early 2004 (before Aulacaspis yasumatsui reached this habitat) to 87 individuals in January 2007.[1] In 2004, Rhyzobius lophanthae was employed on Guam as a biological pest control and has lessened the population decline. However, they were ineffective on protecting cycad seedlings from Aulacaspis yasumatsui predation, as lack of seed vigor is one of the major factors contributing to C. micronesica decline.[14] without effective action against the Aulacaspis scale, it may become critically endangered. It used to have stable populations across Micronesia, with Guam having the largest. However, the Aulacaspis scale invasion caused an 87% decline in the Guam subpopulation over ten years.[15]

Threats edit

The Cycad Aulacaspis scale, an invasive species from Southeast Asia, poses a significant threat to Cycas micronesica, resulting in substantial plant mortality. However, it's crucial to emphasize that the current plant mortality is not solely due to this scale. The introduction of the Cycad Blue Butterfly in 2005 and the intensified damage caused by pre-existing arthropod pests are additional severe threats to the already weakened cycad population. Longhorn beetles, especially Acalolepta marianarum, are responsible for many recent plant deaths due to stem damage. Moreover, the invasive snail Satsuma mercatoria has emerged as a new and significant threat by feeding on young leaflets. This change in herbivore behavior may be a result of the compromised ability of unhealthy cycad plants to synthesize chemicals that deter herbivores. These threats collectively imperil the survival of Cycas micronesica.[15]

Gallery edit

  •  
    Understory habitation
  •  
    Pinnate leaf formation
  •  
    Stem and palm-like structure
  •  
    Female reproductive structures (megasporangia)
  •  
    Male cones (microsporangia)
  •  
    Fertilized megasporangia with developing seeds
  •  
    Infestation by the armored scale on the male cone
  •  
    Developed seed

See also edit

References edit

  1. ^ a b c Bösenberg, J.D. (2022). "Cycas micronesica". IUCN Red List of Threatened Species. 2022: e.T61316A68906033. doi:10.2305/IUCN.UK.2022-1.RLTS.T61316A68906033.en. Retrieved 22 August 2023.
  2. ^ Hill, K.D. (1994). Cycas micronesica. Australian Systematic Botany 7: 554-556.
  3. ^ Athens, J., & Ward, J. (2004). Holocene vegetation, savanna origins and human settlement of Guam. Records Of The Australian Museum, 15-30.
  4. ^ Sacks, Oliver. (1996). The Island of the Colour-blind. Pan Macmillan Australia: Sydney. ISBN 0-330-35887-1
  5. ^ Cox PA, Banack SA, Murch SJ, Rasmussen U, Tien G, Bidigare RR, Metcalf JS, Morrison LF, Codd GA, Bergman B (2005). "Diverse taxa of cyanobacteria produce b-N-methylamino-L-alanine, a neurotoxic amino acid". PNAS. 102 (14): 5074–5078. Bibcode:2005PNAS..102.5074C. doi:10.1073/pnas.0501526102. PMC 555964. PMID 15809446.
  6. ^ Esterhuizen M, Downing TG (2008). "β-N-methylamino-L-alanine (BMAA) in novel South African cyanobacterial isolates". Ecotoxicology and Environmental Safety. 71 (2): 309–313. doi:10.1016/j.ecoenv.2008.04.010. PMID 18538391.
  7. ^ Vogt, S., & Williams, L. (2004). Common flora & fauna of the Mariana Islands. Saipan?: S.R. Vogt & L.L. Williams.
  8. ^ a b Hill KD (1994). "The Cycas rumphii complex (Cycadaceae) in New Guinea and the western Pacific". Australian Systematic Botany. 7 (6): 543–567. doi:10.1071/sb9940543. ISSN 1446-5701.
  9. ^ Willis, K., & McElwain, J. C. (2014). The evolution of plants (2nd ed.). Oxford, United Kingdom; New York: Oxford University Press.
  10. ^ Terry, Irene; & Marler, Thomas. (2005). Paradise Lost? Tipping the scales against Guam’s Cycas micronesica. The Cycad Newsletter 28(3-4): 21-23.
  11. ^ Donnegan, J., & Pacific Northwest Research Station. (2004). Guam's forest resources, 2002 (Resource bulletin PNW ; 243). Portland, OR: U.S. Dept. of Agriculture, Forest Service, Pacific Northwest Research Station.
  12. ^ Marler, T.E.; Lawrence, J.H. (2012). "Demography of Cycas micronesica on Guam following introduction of the armoured scale Aulacaspis yasumatsui". Journal of Tropical Ecology. 28 (3): 233–242. doi:10.1017/S0266467412000119.
  13. ^ Marler, T.E. (2010). "Cycad mutualist offers more than pollen transport". American Journal of Botany. 97 (5): 841–845. JSTOR 20700414.
  14. ^ Marler, T.E.; Miller, R.; Moore, A. (2013). "Vertical Stratification of Predation on Aulacaspis yasumatsui Infesting Cycas micronesica Seedlings". HortScience. 48 (1): 60–62. doi:10.21273/HORTSCI.48.1.60.
  15. ^ a b "Redlist - Cycas micronesica".

External links edit

  • The Cycad Pages – Cycas micronesica 2014-06-23 at the Wayback Machine
  • Plants of Guam [Botanical]- University of Guam College of Natural Arts and Sciences
  • Flickr: Plants of Guam by Lauren Gutierrez - Cycas micronesica K.D. Hill
  • Guam Plant Extinction Prevention Program

"Home". Guam Plant Extinction Prevention Program. Retrieved 2018-06-08.

May 11, 2024
cycas, micronesica, species, cycad, found, island, micronesia, marianas, islands, guam, rota, republic, palau, commonly, known, federico, fadang, chamorro, species, previously, lumped, with, cycas, rumphii, cycas, circinalis, described, 1994, hill, paleoecolog. Cycas micronesica is a species of cycad found on the island of Yap in Micronesia the Marianas islands of Guam and Rota and The Republic of Palau It is commonly known as federico nut or fadang in Chamorro The species previously lumped with Cycas rumphii and Cycas circinalis was described in 1994 by Ken Hill 2 Paleoecological studies have determined that C micronesica has been present on the island of Guam for about 9 000 years 3 It is linked with Lytico Bodig disease a condition similar to amyotrophic lateral sclerosis ALS due to the neurotoxin BMAA found in its seeds which were a traditional food source on Guam until the 1960s 4 The neurotoxin is present due to its symbiosis with cyanobacteria 5 6 Cycas micronesica Conservation status Endangered IUCN 3 1 1 Scientific classification Kingdom Plantae Clade Tracheophytes Clade Gymnospermae Division Cycadophyta Class Cycadopsida Order Cycadales Family Cycadaceae Genus Cycas Species C micronesica Binomial name Cycas micronesicaK D Hill 1994 Contents 1 Description 1 1 Leaves 1 2 Reproductive organs 2 Conservation 3 Threats 4 Gallery 5 See also 6 References 7 External linksDescription editCycas micronesica is a medium sized tree most commonly 2 5 meters tall but can reach heights up to 15 meters The tree has a straight palm like trunk ringed with frond scars 7 Leaves edit Leaves are 140 180 cm long flat in section opposing pinnae inserted at 180 degrees on rhachis with 130 150 pinnae terminated by a spine c 4mm long petiole usually glabrous usually unarmed rarely spinescent for up to 20 of length 35 45 cm long median pinnae at 70 80 degrees to rachis 240 280 mm long 16 17 mm wide 0 35 0 45 mm thick glabrous dull green or slightly bluish green when developing becoming glossy mid green at maturity flat in section with slightly recurved margins strongly discolorous decurrent for 7 10 mm narrowed to 5 0 6 0 mm at base 17 20 mm apart on rhachis apex attenuate midrib not sharply raised more or less equally prominent above and below 1 2 1 5 mm wide 8 Reproductive organs edit Like all cycads Cycas micronesica are dioecious Females possess clusters of ovules situated on modified leaves called megasporophylls Male reproductive structures consist of modified leaves called microsporophylls but each modified leaf has small compact pollen sacks attached to their lower surface 9 There has been documentation of the symbiotic relationship the Guamanian C micronesica with Anatrachyntis sp which depends on male cones microsporangia for oviposition and recruitment in return for pollinating the species The microsporangiate cones are pale fawn to pale orange brown narrowly ovoid 30 50 cm long 8 10 cm in diameter Microsporophyll lamina are 35 45 mm long 20 25 mm wide fertile zone 25 35 mm long sterile apex 7 10 mm long not recurved apical spine somewhat reduced broad sharply upturned 2 mm long Megasporophylls 27 33 cm long grey and orange tomentose with 2 6 ovules lamina 45 55 mm wide broadly ovate to elliptical regularly dentate with 16 20 lateral spines apical spine 8 15 mm long lateral spines 2 6 mm long Seeds flatten to ovoid green becoming orange not pruinose 50 60 mm long 45 50 mm in diameter sarcotesta 3 6 mm thick 8 Conservation editCycas micronesica is threatened by a combination of introduced species throughout the islands of Guam and Rota The most notable pest is the diaspidid scale Aulacaspis yasumatsui which was first recognized in Guam in December 2003 10 Other threats include cycad blue butterfly Luthrodes pandava the longhorn beetle Acalolepta marianarum which causes stem damage the alien invasive snail Satsuma mercatoria which feeds on young leaflets and habitat loss due to the growing human population 1 Prior to the invasion of Aulacaspis yasumatsui it was one of the most abundant plants in Guam s forests 11 Plant mortality was so rapid that the species was Red Listed as Endangered in 2006 only three years after the devastating invasions began 12 13 Population counts in northwest Guam have declined from 686 individuals in early 2004 before Aulacaspis yasumatsui reached this habitat to 87 individuals in January 2007 1 In 2004 Rhyzobius lophanthae was employed on Guam as a biological pest control and has lessened the population decline However they were ineffective on protecting cycad seedlings from Aulacaspis yasumatsui predation as lack of seed vigor is one of the major factors contributing to C micronesica decline 14 without effective action against the Aulacaspis scale it may become critically endangered It used to have stable populations across Micronesia with Guam having the largest However the Aulacaspis scale invasion caused an 87 decline in the Guam subpopulation over ten years 15 Threats editThe Cycad Aulacaspis scale an invasive species from Southeast Asia poses a significant threat to Cycas micronesica resulting in substantial plant mortality However it s crucial to emphasize that the current plant mortality is not solely due to this scale The introduction of the Cycad Blue Butterfly in 2005 and the intensified damage caused by pre existing arthropod pests are additional severe threats to the already weakened cycad population Longhorn beetles especially Acalolepta marianarum are responsible for many recent plant deaths due to stem damage Moreover the invasive snail Satsuma mercatoria has emerged as a new and significant threat by feeding on young leaflets This change in herbivore behavior may be a result of the compromised ability of unhealthy cycad plants to synthesize chemicals that deter herbivores These threats collectively imperil the survival of Cycas micronesica 15 Gallery edit nbsp Understory habitation nbsp Pinnate leaf formation nbsp Stem and palm like structure nbsp Female reproductive structures megasporangia nbsp Male cones microsporangia nbsp Fertilized megasporangia with developing seeds nbsp Infestation by the armored scale on the male cone nbsp Developed seedSee also editList of endemic plants in the Mariana IslandsReferences edit a b c Bosenberg J D 2022 Cycas micronesica IUCN Red List of Threatened Species 2022 e T61316A68906033 doi 10 2305 IUCN UK 2022 1 RLTS T61316A68906033 en Retrieved 22 August 2023 Hill K D 1994 Cycas micronesica Australian Systematic Botany 7 554 556 Athens J amp Ward J 2004 Holocene vegetation savanna origins and human settlement of Guam Records Of The Australian Museum 15 30 Sacks Oliver 1996 The Island of the Colour blind Pan Macmillan Australia Sydney ISBN 0 330 35887 1 Cox PA Banack SA Murch SJ Rasmussen U Tien G Bidigare RR Metcalf JS Morrison LF Codd GA Bergman B 2005 Diverse taxa of cyanobacteria produce b N methylamino L alanine a neurotoxic amino acid PNAS 102 14 5074 5078 Bibcode 2005PNAS 102 5074C doi 10 1073 pnas 0501526102 PMC 555964 PMID 15809446 Esterhuizen M Downing TG 2008 b N methylamino L alanine BMAA in novel South African cyanobacterial isolates Ecotoxicology and Environmental Safety 71 2 309 313 doi 10 1016 j ecoenv 2008 04 010 PMID 18538391 Vogt S amp Williams L 2004 Common flora amp fauna of the Mariana Islands Saipan S R Vogt amp L L Williams a b Hill KD 1994 The Cycas rumphii complex Cycadaceae in New Guinea and the western Pacific Australian Systematic Botany 7 6 543 567 doi 10 1071 sb9940543 ISSN 1446 5701 Willis K amp McElwain J C 2014 The evolution of plants 2nd ed Oxford United Kingdom New York Oxford University Press Terry Irene amp Marler Thomas 2005 Paradise Lost Tipping the scales against Guam s Cycas micronesica The Cycad Newsletter 28 3 4 21 23 Donnegan J amp Pacific Northwest Research Station 2004 Guam s forest resources 2002 Resource bulletin PNW 243 Portland OR U S Dept of Agriculture Forest Service Pacific Northwest Research Station Marler T E Lawrence J H 2012 Demography of Cycas micronesica on Guam following introduction of the armoured scale Aulacaspis yasumatsui Journal of Tropical Ecology 28 3 233 242 doi 10 1017 S0266467412000119 Marler T E 2010 Cycad mutualist offers more than pollen transport American Journal of Botany 97 5 841 845 JSTOR 20700414 Marler T E Miller R Moore A 2013 Vertical Stratification of Predation on Aulacaspis yasumatsui Infesting Cycas micronesica Seedlings HortScience 48 1 60 62 doi 10 21273 HORTSCI 48 1 60 a b Redlist Cycas micronesica External links editThe Cycad Pages Cycas micronesica Archived 2014 06 23 at the Wayback Machine Plants of Guam Botanical University of Guam College of Natural Arts and Sciences Flickr Plants of Guam by Lauren Gutierrez Cycas micronesica K D Hill Guam Plant Extinction Prevention Program Home Guam Plant Extinction Prevention Program Retrieved 2018 06 08 Retrieved from https en wikipedia org w index php title Cycas micronesica amp oldid 1192984416, wikipedia, wiki, book, books, library,

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