10 Most Unusual Flowers


Sea Holly (Eryngium)

Sea holly is also known as Rattlesnake-Master, Sea Holm, Spiny Cilantro and Miss Wilmott's Ghost.
Sea holly is also known as Rattlesnake-Master, Sea Holm, Spiny Cilantro and Miss Wilmott's Ghost.
©iStockphoto.com/Paul Cowan

If you're into the blues, sea hollies will hit the top 10 in your garden. This odd-looking flower sports an elongated cone of tiny blue flowers on a platform of spiny blue-green bracts at the top of metallic blue stems.

Also known as Rattlesnake-Master, Sea Holm, Spiny Cilantro and Miss Wilmott's Ghost, these hardy and semi-hardy perennials bloom in the latter half of summer. They're big plants, ranging from 18 to 36 inches (46 to 91 centimeters) high with a one-foot (30-centimeter) spread [source: Deem-Reilly]. They appreciate a little help through dry periods, and may need staking if you live in a windy area, but they're tough enough to look after themselves for the most part. They're hardy to USDA zone 5.

Sea hollies are native to Iran and the Caucasus, but some species grow wild in the United States. They're related to Queen Anne's lace, parsley, fennel and anise. Although they have no fragrance, Eryngium attract butterflies. The flowers make an interesting addition to fresh-cut displays and dry well for dried arrangements.

Sea hollies need full sun and moist soil with good drainage. They grow from a deep taproot. This helps them survive droughts, but it makes them difficult to divide or relocate. Fortunately, they're easy to grow from seed. It may take a while to get them started, though. Collected seeds should be refrigerated for three weeks. Once planted in the garden, it may take up to 10 weeks before the seeds germinate. New plants probably won't bloom in their first year. Before you put a lot of effort into this method, make sure that the sea holly you collect seeds from is a naturally occurring species. Hybrids or cultivars may be sterile, and are unlikely to grow true to the parent plant if they do germinate.

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  • Bawden-Davis, Julie. Flower Gardening: A Practical Guide to Creating Colorful Gardens in Every Yard. New York: Readers Digest, 2004.
  • Calyx Flowers. "Sea Holly." (Accessed 10/08/2009). http://www.calyxflowers.com/Floral-Library/Content/Sea-Holly.aspx
  • Casey, Carol. "Carnivorous Plants Whet Appetite for Learning." Washington College Magazine: Spring 2000. (Accessed 10/08/2009). http://www.washcoll.edu/wc/news/washmag/spring2000/00_spring_13.html
  • Chafin, Linda G. Field Guide to the Rare Plants of Georgia. Athens: The State Botanical Garden of Georgia and the Georgia Conservation Alliance, 2007.
  • Chittka, Lars with Avi Schmida, Nikolaus Troje, and Randolf Menzel. "Ultraviolet as a Component of Flower Reflections, and the Colour Perception of Hymenoptera." Elsevier Science Ltd. 1994. (Accessed 10/12/2009). http://www.biomotionlab.ca/Text/chittka_VR_94.pdf
  • D'Amato, Peter. The Savage Garden: Cultivating Carnivorous Plants. Berkeley: Ten Speed Press, 1998.
  • Darwin, Charles. Insectivorous Plants. New York: D. Appleton and Company, 1875. Project Gutenberg. (Accessed 10/08/2009). http://www.gutenberg.org/etext/5765
  • Deem-Reilly, Terry. "Sea Holly: Eryngium." Colorado State University Cooperative Extension, Denver. January 4, 2009. (Accessed 10/08/2009). http://www.coopext.colostate.edu/4DMG/Flowers/Perenls/seaholly.htm
  • Earlham College. "The Genus Rafflesia." Biological Diversity 2003. (Accessed 10/11/2009). http://www.earlham.edu/~givenbe/Rafflesia/rafflesia/biodiv2.htm
  • Economic Research Service. "Floriculture and Nursery Crops Yearbook -- Summary." United States Department of Agriculture. September 28, 2007. (Accessed 10/07/2009). http://www.ers.usda.gov/Publications/Flo/2007/09Sep/FLO2007s.txt
  • Greer, Germaine. "Country Notebook: Ellen Wilmott." Telegraph.co.uk: April 19, 2003. (Accessed 10/15/2009). http://www.telegraph.co.uk/gardening/gardenprojects/3310290/Country-notebook-Ellen-Willmott.html
  • Kanapaux, Bill. "Evolution of the First Flowers." The Florida Museum of Natural History. Natural History Magazine, August 8, 2009. (Accessed 10/06/2009). http://www.naturalhistorymag.com/partner/florida-highlight-sept
  • Kew Gardens. "Titan arum." Kew Garden website. (Accessed 10/07/2009). http://www.kew.org/plants/titan/history.html
  • Ladyman, Juanita A.R. "Cereus greggii Englemann." JnJ Associates. (Accessed 10/12/2009). http://www.fs.fed.us/global/iitf/pdf/shrubs/Cereus%20greggii.pdf
  • Leeward Community College. "Animal Pollinators." Plants in the Hawaiian Environment. University of Hawaii Distance Education Web. (Accessed 10/12/2009). http://emedia.leeward.hawaii.edu/millen/bot130/learning_objectives/lo07/07.html
  • Lloyd, Christopher. Color for Adventurous Gardeners. London: Firefly Books, 2001.
  • Marent, Thomas with Ben Morgan. Rainforest. New York: DK Publishing, 2006.
  • Markham, Kenneth R. and Stephen J. Bloor, Rob Nicholson, Paul Rivera, Melvin Shemluck, Peter G. Kevan, and Charles Michener. "Black Flower Coloration in Lisianthius nigrescens: Its Chemistry and Ecological Consequences." July 6, 2004. (Accessed 10/08/2009). http://www.znaturforsch.com/ac/v59c/s59c0625.pdf
  • Raffles Museum of Biodiversity Research. "Sir Thomas Stamford Raffles, 1781-1826." Department of Biological Sciences, University of Singapore. 2000. (Accessed 10/11/2009). http://rmbr.nus.edu.sg/history/raffles.htm
  • Royo, A.R. "Night-Blooming Cereus." Exploring the Southwest Desert USA: July 1999. (Accessed 10/08/2009). http://www.desertusa.com/mag99/july/papr/nbcereus.html
  • Souza, D.M. Freaky Flowers. New York: Franklin Watts, 2002.
  • Stern, Marc. "Kniphofia Moench." Witwatersrand National Botanical Garden: July 2002. (Accessed 10/08/2009). http://www.plantzafrica.com/plantklm/kniphofias.htm
  • The Garden Helper. "How to Grow Torch Lilly . . . Red Hot Poker." November 5, 1999. (Accessed 10/08/2009). http://www.thegardenhelper.com/tritoma.html
  • Thomas, Paul A. "Growing Orchids." Horticulture Fact Sheet H-93-013. The University of Georgia College of Agricultural and Environmental Sciences Cooperative Extension Service. (Accessed 10/07/2009). http://pubs.caes.uga.edu/caespubs/horticulture/orchids.html
  • University of Arkansas. "Night Blooming Cereus." Division of Agriculture. Cooperative Extension Service. July 15, 2009. (Accessed 10/08/2009). http://www.arhomeandgarden.org/landscaping/SpecGardening/night_blooming_cereus.htm
  • University of California Museum of Paleontology. "Introduction to Anthophyta, the flowering plants." University of California, Berkeley, 2009. (Accessed 10/06/2009). http://www.ucmp.berkeley.edu/anthophyta/anthophyta.html
  • University of Connecticut. "Amorphophallus titanium." Ecology and Evolutionary Biology Plant Growth Facilities. College of Arts and Sciences. October 6, 2009. (Accessed 10/07/2009). http://florawww.eeb.uconn.edu/199500115.html
  • Wahlert, John H. and Mary Jean Holland. "Division Anthophyta (Angiosperms): Flowering Plants." Baruch College, City University of New York. September 22, 2007. (Accessed 10/06/2009). http://faculty.baruch.cuny.edu/jwahlert/bio1003/anthophyta.html


New Sharing Website Links Farmers, Saves Seeds

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A new website is designed to bring farmers and heirloom seeds together. HowStuffWorks takes a look at why seed saving is more important than ever.