Sunday, November 17, 2013

Highly invasive Pennisetum purpureum, aka Giant King Grass, as requested by Richard R. Rodriguez, CPA in a comment post request

Pennisetum purpureum (Schumach. 1827)
NPS photo by National Tropical Botanical Gardens

Normally I would just post his comment, but given the nature of hiscomments, I thought he was owed a more detailed response.

Here are his comments: 

"Need more information from your research to agree with your statements. Giant King Grass is NOT invasive.Giant King Grass actually has 80% of its roots mass in the top 18 to 24” of the soil. The other 20% are small hair like roots that can ...go deeper and break down each year and regenerate new roots. In summary, very little of the root system is deeper than 24”. The roots could never get to an aquifer. A major benefit of GKG is its ability to stop run off water and erosion loss of surface water that would normally run into the ocean". 

Mr. Rodriguez, CPA, in his request for more information on this invasive plant mentions root depth which is not part of any weed risk assessment currently used in the United States (or for that matter anywhere else I know about).

Here, then is the information from the University of Hawai'i's risk assessment of the highly invasive species Pennisetum purpureum (Schumach. 1827) as requested by Mr. Richard R. Rodriguez, CPA:

4.01      Produces spines, thorns or burrs     y=1, n=0            n            No evidence of spines, thorns or burrs.           Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press. Honolulu.
4.02      Allelopathic    y=1, n=0            n            Not allelopathic.     
4.03      Parasitic           y=1, n=0            n            No evidence.  
4.04      Unpalatable to grazing animals         y=1, n=-1          n            (1)Medium palatability. (2)The grass is valued for its … palatability…'               (1)   (2)Bogdan, A.V. 1977. Tropical pasture and fodder plants. Longman, London
4.05      Toxic to animals          y=1, n=0            n            "(1)Not toxic.   (2)Seiler et al. (1979) report fatal nitrate poisonings in cattle whose diet consisted solely of Napier grass. Levels of nitrate averaged 28.3 mg/g with some samples as high as 44 mg which levels in the same species from non-toxic areas was 3.9 mg/g. (due to grown in soil with excessive N) 3)It is one of the most valuable forage, soilage and silage crops in the wet tropics
"             (1)  (2) 3)
4.06      Host for recognized pests and pathogens   y=1, n=0            n            This website lists 88 species of fungi that are found on P. purpureum (only a few generalists are economically important.)
4.07      Causes allergies or is otherwise toxic to humans  y=1, n=0            n            No evidence.         
4.08      Creates a fire hazard in natural ecosystems             y=1, n=0                           Not fire resistant and high fire tolerance.
4.09      Is a shade tolerant plant at some stage of its life cycle       y=1, n=0            n               Shade intolerant.
4.1         Tolerates a wide range of soil conditions (or limestone conditions if not a volcanic island)           y=1, n=0            y             1) It is a rapid colonizer of disturbed areas and prospers in a broad range of conditions. 2)Requires a rich soil 3)However, it will also grow on poorly drained soils to dry sandy soils of low fertility.        1) 2) 3)
4.11      Climbing or smothering growth habit          y=1, n=0            n            No evidence. Not a vine.
4.12      Forms dense thickets              y=1, n=0            y               'Forms dense perennial stands, difficult to penetrate, which inhibits establishment of other vegetation.'      
5.01      Aquatic             y=5, n=0            n            Semi-aquatic grass     
5.02      Grass   y=1, n=0            y             Perennial grass.     
5.03      Nitrogen fixing woody plant               y=1, n=0            n                          
5.04      Geophyte (herbaceous with underground storage organs -- bulbs, corms, or tubers)              y=1, n=0            n                          
6.01      Evidence of substantial reproductive failure in native habitat     y=1, n=0            n               No evidence.  
6.02      Produces viable seed.              y=1, n=-1          y             if grown from seed, it is started in a nursery and transplanted     
6.03      Hybridizes naturally y=1, n=-1                         (1)P. purpureum hybridizes with P. americanum readily under artificial conditions. No evidence of natural hybridization.  (2) 'Many cultivars and hybrids occur, a well known example is Banagrass, a cross with P. glaucum.' - again no evidence that this occurs naturally.            Bogdan, A.V. 1977. Tropical pasture and fodder plants. Longman, London
6.04      Self-compatible or apomictic             y=1, n=-1          y             A selfed progeny of the 'Merkeron' cultivar was produced (also, likely to be apomictic)     
6.05      Requires specialist pollinators          y=-1, n=0          n            Probably not. Most grasses are wind pollinated - the flower morphology does not reveal adaptation to a specialist pollinator.
6.06      Reproduction by vegetative fragmentation              y=1, n=-1          y             is sometimes stoloniferous with a creeping rhizome. (sreads slowly this way)     
6.07      Minimum generative time (years)                 1 year = 1, 2 or 3 years = 0, 4+ years = -1            See left               1            R. Criley, UH department of Horticulture (but assessment was given with low confidence, could required 2 years) 
7.01      Propagules likely to be dispersed unintentionally (plants growing in heavily trafficked areas)         y=1, n=-1          n            Propagules do not have any means of attachment.   
7.02      Propagules dispersed intentionally by people         y=1, n=-1          y             Pasture grass, sometimes grown as an ornamental.             
7.03      Propagules likely to disperse as a produce contaminant  y=1, n=-1          y               "Weed: potential seed contaminant (fide Weed CIBA)
(Stalks are cut and transported for feeding livestock. Some seeds are likely transported (accidentally) in the process)"
7.04      Propagules adapted to wind dispersal         y=1, n=-1          y             plumose spikelets          
7.05      Propagules water dispersed               y=1, n=-1          n                          
7.06      Propagules bird dispersed    y=1, n=-1          n                          
7.07      Propagules dispersed by other animals (externally)          y=1, n=-1          n               Propagules do not have any means of attachment.             
7.08      Propagules survive passage through the gut            y=1, n=-1          n            No evidence.         
8.01      Prolific seed production (>1000/m2)          y=1, n=-1          n            'Pennisetum purpureum produces, with occasional exception little or no seed, …'     Bogdan, A.V. 1977. Tropical pasture and fodder plants. Longman, London
8.02      Evidence that a persistent propagule bank is formed (>1 yr)       y=1, n=-1          n               (1)Caryposis 2 mm long.   (2)'Pennisetum purpureum produces, with occasional exception little or no seed, …'3)Does not readily produce viable seed in many countries,               (1)Wagner,W. L., D. R. Herbst & S. H. Sohmer. 1990. Manual of flowering plants of Hawaii.University of Hawaii at Press.   (2)Bogdan, A.V. 1977. Tropical pasture and fodder plants. Longman, London 3)
8.03      Well controlled by herbicides             y=-1, n=1          y             "(1)Foliar application of 1%-3% Roundup Pro. If non-target damage is a concern, cut stems to ground level and allow sprouts to reach 8-12 inches and treat the same as Neyraudia above. Broadcast 3-5 quart/acre Roundup Pro, 2 quart/acre Arsenal, or 1 quart Arsenal and 2 quart Roundup Pro.
(2)The herbicide glyphosate provides acceptable control in aquatic sites "               (1)  (2)
8.04      Tolerates, or benefits from, mutilation, cultivation, or fire             y=1, n=-1          y               1) No resprout ability. 2)Resprouts easily from small rhizomes left after mechanical control 3) regrows following frequent clipping (harvesting for animal fodder)              1) 2) 3)
8.05      Effective natural enemies present locally (e.g. introduced biocontrol agents)   y=-1, n=1                 Biological controls for napier grass are unknown in Florida.      
               Total score:                    16          -> Highly Invasive

Risk assessment from University of Hawai'i             

Wednesday, October 23, 2013

Inspecting Invaders by Robert Davison - A new Blog about Invasive Species

               When I started this blog in 2006, there were few places to go to find information and more importantly, explanations about invasive species and their impacts. There were, of course, technical websites and list-serves with detailed information, but there were few entryways for the general public to support a high level understanding of the effects of invasive species on the landscapes of the immediate ecosystem in which they were encountered.

               A new blog has caught my attention for its deft use of metaphor that brings an additional way of clearly understanding the complex issues that surround invasive species. Inspecting Invaders has but three postings so far, but each is worth a read. The blog author, Robert Davison, chooses a feature of invasion ecology, and subjects using metaphor and fact to examination succinctly bring home the salient impact of invasive species. "Imagine you're about to race Usain Bolt" is an unlikely sentence in any description of invasion biology, but surely grabs your attention because it is so improbable a start to explaining invasive species establishment and the impact of spread.

               I hope Mr. Davison continues his work, and this blog, and continues his investigations and clear explications of the many facets of invasive species biology and policy.

               Check out his blog and encourage him to do more!

Friday, September 20, 2013

Challenge of Ecosystem Conservation and Sustainability Rests with Relatively Affluent People

            What if the challenge of ecosystem conservation and sustainability actually rest with the relatively affluent people who already live here that are ruining the Chesapeake Bay, and not the world's masses fleeing oppression and seeking a better life (v. Immigration is an environmental issue September 03, 2013| By Tom Horton) ?


            Fred Tutman, the Patuxent Riverkeeper asks, "Isn't it the technologically advanced nations that contribute most to the loss of greenhouse gasses and create climate effects that give rise to drought, famine and floods? Aren't some immigrants refugees of ecological catastrophes in their own homelands?"


            Tutman has given me permission to post his comments in full.


            "I think that if the Bay were populated primarily by immigrant populations it would possible be better off than than under the current population and regime that seeks to preserve a certain social status qou (albeit while cleaning up the trash and saving turtles) instead of seeking ways to share our natural resource wealth with those humans less fortunate than ourselves.

            When we speak of "population" in abstract terms it gives rise to why some detractors see environmentalists as lacking in compassion. We appear to be all about protecting the earth without much stomach for addressing the plight of its human population--aside from assessing how surplus populations threaten our 1st world incumbency.

            So not only is population a tough subject, it is one potentially laden with classist significance depending on who is doing the finger pointing and making the policy recommendations. That's all I was trying to convey. That the Chesapeake Bay is perhaps not the best illustrator of forum for population concerns.

            The troubling thing that I have learned after ten years of Riverkeeping is that the movement to address this problem (i.e poverty, population etc), has almost nothing at all to do with the "Save the Bay" cause movement as currently configured. In fact "Baysavers" will for the most part struggle to keep the focus on natural resources rather than on human impacts and problems. So, the aim to save crabs and oysters has managed cheerfully (and sadly) to isolate itself from much striving to restore justice and fairness to actual people and communities. The more I travel and interact with other environmentalists outside of the Bay States, the more I realize how ideologically parochial our regional movement has become.  

            Moreover, because of who generally funds and controls environmental movements in our society, there is far more interest in saving nature than in protecting the oppressed and those with few hopes of environmental decency or dignity-- or for that matter very little bandwidth for expanding our potential as humans who live in a natural world. We'll "educate" folks before we will use our powers of activism to help them acquire a living in a decent environment.  The mere mention of the term "environmental justice" conjures up visions of minorities or civil rights which many in our movement see as way "off message" for "the Bay" or at least a separate and far less fundable movement. Actually these themes are much more  fundamental and complex and really hard to control. In fact, they are problems way bigger in scope than the primary focus of Tom Horton's article (the Bay).

            My overall point is, changing the dialogue or its frame of reference generally alters who gets to control the messaging and who reaps the benefits of our efforts. So for me at least, this is ultimately just as much about freeing the minds of those with the most influence over what we regard as "environmentalism" and challenging entitlements. By the way, I have noted that while 1% funders do not always directly tell us what we can and cannot work on, nonetheless funding considerations often severely limit the range of ideas and themes many of us are willing to consider.

            While my ideas are not at all fixed on any of these points, I am always eager to find ways to look at environmental problems with a different lens. The old one hasn't work as well as I might like."

            Environmental justice is a major issue that rarely comes up in ecosystem discussions, a fact about which I have commented in 2008 in a blog post on this site: Minority involvement in environmental conversations.

Tuesday, September 17, 2013

Beefsteak plant, (Perilla frutescens), a Growing Control Problem

Beefsteak plant flower
               Natural areas, parks and woods of the Lower Chesapeake Bay have yet another early detection of a non indigenous, alien species.  Perilla frutescens (L.) Britton 1894, [synonyms: Ocimum frutescens L.; Perilla ocymoides L.] beefsteak plant, has been found to be spreading beyond Maryland's cultivated, managed gardens and landscapes. Escaped from gardens in New York as early as 1898, it was reported as a weed of wastelands.[1]  Bernard McMahon, the great American horticulturalist, was selling Perilla seed as early as 1804.[2] Marc Imlay, the great weed warrior, has been weeding Perilla from parks in Maryland since 1998.[3]

               Beefsteak plant also known as Chinese basil; purple or perilla mint, is described on the Missori Botanical Garden website as

"an upright, bushy annual that is native from the Himalayas to Southeast Asia. It is related to coleus and basil. It has become a very popular foliage annual and salad herb plant. It grows to 1-3’ (less frequently to 4’) tall. Wrinkled, serrate, broad ovate, medium green leaves (to 4” long) are sometimes tinged with purple. Leaves are aromatic. Two-lipped nettle-like white flowers in spike-like inflorescences (to 4”) bloom at the stem tips in late summer and fall (August – October). Flowers are not particularly showy. This plant has escaped gardens and naturalized throughout many areas of the eastern and central U. S., including central and southern Missouri. Fresh leaves are used in Oriental cooking, salads, soups and as garnishes. Deep red leaves of some perilla varieties purportedly resemble the color of uncooked beef, hence the common name."

USDA Plants - spread of Purilla frutescens
               Perilla frutescens is reported as invasive in DC, IL, MD, MO, PA, TN, VA,
and WV and occurring in all states east of Colorado, parts of Canada, as well as the State of Washington on the west coast (excluding, for now, the Dakotas). The Forest Service (USDA) is aware that beefsteak plant is often planted as showy ornamentals,  that

"may readily escape cultivation, spreading to disturbed areas where they disrupt native ecosystems. The species has toxic characteristics and very few predators. It is ordinarily avoided by cattle and has been implicated in cattle poisoning. Plants are most toxic if cut and dried for hay late in the summer, during seed production. One reason for beefsteak plants’ survival in pastures is that cattle avoid it. Sold as a salad plant for its dark purple foliage, this member of the mint family is extremely invasive by wind-borne seeds."[4]

Chinese basil or perilla mint - Perilla frutescens
               Purdue Extension Service website control recommendations include "...pulling or digging it up, mowing it, or using herbicides. 2,4-D, Milestone®, Forefront®, Weedmaster®, and glyphosate."  Dr. Imlay, however, notes an ominous sign that control of Perilla frutescens, as well as control of Japanese stiltgrass, Microsteigum virineum Camus 1921[1922], is becoming much more difficult. Imlay told me that he and his volunteers removed 100% of the beefsteak plants by hand pulling until 2010 when many newly emergent patches in open space and lightly shaded areas emerged. He also noted that  existing patches of Perilla frutescens  no longer declined by ~80 % each year in 'weeded'  sections of the park as they had in previous years. 

               "In 2010," Imlay said, " I switched to herbicide treatment and sprayed 20 gallons. A great reduction occurred in 2011 and I only had to spray 2.2 gallons along with modest hand pulling. However, in 2012 many new patches appeared, all of which were treated or hand pulled. But this year many, many new and expanded patches have appeared increasing the coverage of beefsteak plant from about 1/10 th acre to about 1/2 acre.  As of September 6 we have already sprayed 60 gallons and only sprayed about half of the beefsteak plant."

         While preventing and introduction is the first line of defense, even the best prevention efforts will not stop all harmful invasive species. In the case of beefsteak plant, however, preventing its introduction has been off the table for over 200 years. However using the tools of IPM (Integrated Pest Management), such as early detection and rapid response (EDRR), at a local level can greatly support effective management and even in some cases elimination. EDRR efforts increase the likelihood that invasions that can lead to establishment and spread of harmful species will be halted and eradicated. Once a species becomes widely established in an ecosystem, the only action possible is the partial mitigation of negative impacts. Based on the work of the ISAC/NISC EDRR Subcommittee, NISC has approved Guidelines for Early Detection and Rapid Response. 

Additional References
Ali, S.I., Raven, P.H. & Hoch, P., 2012. Flora of Pakistan Perilla frutescens (L.) Britton. Flora of Pakistan. Available at: [Accessed April 2, 2012].
Brenner, D.M., 1993. Perilla: Botany, uses and genetic resources. In J. Janick & J. E. Simon, eds. New Crops. New York, NY USA: John. Wiley & sons, inc., pp. 322–328. Available at:
Britton, N.L., 1894. List of Pteridophyta and Spermatophyta growing without Cultivation in Northeastern North America. Committee of the Botanical Club American Association for the Advancement of Science, ed. Memoirs of the Torrey Botanical Club, 5(18), p.277. Available at: [Accessed April 2, 2012].
Britton, N.L. & Brown, A., 1898. An illustrated flora of the northern United States: Canada and the British possessions from Newfoundland to the parallel of the southern boundary of Virginia, and from the Atlantic ocean westward to the 102d meridian, C. Scribner’s Sons. Available at:
Brouillet, L., Coursol;, F. & Favreau, M., 2012. VASCAN. Database of Vascular Plants of Canada (VASCAN). Available at: [Accessed April 3, 2012].
Burton, R.H., 1933. Perilla frutescens; North America; USA; Connecticut; Middlesex County. Yale Peabody Museum of Natural History. Available at: 1385009&SU=0 [Accessed April 2, 2012].
Chen, J. et al., 1997. Plant Distribution and Diversity Across an Ozark Landscape, Available at:
Douce, G.K. et al., 2005. a Web-based Image Archive and Database System Focused on North American Exotic and Invasive Species. In K. W. Gottschalk, ed. Proceedings, XV U.S. Department of Agriculture interagency research forum on gypsy moth and other invasive species 2004. U.S. Department of Agriculture, Forest Service, Northeastern Research Station.
Dӧnmez, A.A., 2002. Perilla: a New Genus for Turkey. Turk J Bot, 26, pp.281–283. Available at:
Eames, E.H., 1916. Perilla frutescens; North America; USA; Connecticut; Fairfield County. Yale Peabody Museum of Natural History. Available at: 1385010&SU=0 [Accessed April 2, 2012].
Everest, J.W., Powe Jr., T.A. & Freeman, J.D., 2006. Poisonous Plants of the Southeastern United States, Available at:
Forest Health Staff, 2005. Beefsteak Plant: Perilla frutescens (L.) Britt.
GBIF ed., 2012. GBIF. In Global Biodiversity Information Facility. Available at: [Accessed April 4, 2012].
Harger, E.B., 1901. Perilla frutescens; North America; USA; Connecticut; New Haven County. Yale Peabody Museum of Natural History. Available at: 1379606&SU=0 [Accessed April 2, 2012].
Honda, G. et al., 1994. Genetic control of geranial formation in Perilla frutescens. Biochemical Genetics, 32(5-6), pp.155–159.
Hwang, L.S., 1997. Anthocyanins from Perilla. In H.-C. Yu, K. Kosuna, & M. Haga, eds. Perilla; the genus Perilla. Harwood Academy Publishers, p. 171.
Kim, K.-H. et al., 2004. Agrobacterium-mediated genetic transformation of Perilla frutescens. Plant Cell Reports, 23(6), pp.386–390.
Kral, R. et al., 2012. Perilla frutescens. Alabama Plant Atlas. Available at: [Accessed April 2, 2012].
Lee, H.R. et al., 1995. Foraging activities and pollination efficacies of the pollinators on the hot pepper (Capsicum annuum), the perilla (Perilla frutescens var. japonica) and the sesame (Sesamum orientale). Korean Journal of Agriculture, 10(2), pp.117–122.
Li, X. & Hedge, I.C., 2008. Flora of China Perilla frutescens (Linnaeus) Britton., 7. Available at: [Accessed April 2, 2012].
Masumoto, N. & Ito, M., 2010. Germination rates of perilla (Perilla frutescens (L.) Britton) mericarps stored at 4 degrees C for 1-20 years. Journal of natural medicines, 64(3), pp.378–382.
Negi, V.S. et al., 2011. Perilla frutescens in Transition: a medicinal and oil yielding plant need instant conservation, a case study from Central Himalaya, India. Environ. We Int. J. Sci. Tech., 6, pp.193–200. Available at:
Press, J.R., Shrestha, K.K. & Sutton, D.A., 2000. Perilla frutescens (L.) Britton. Annotated Checklist of the Flowering Plants of Nepal. Available at: [Accessed April 2, 2012].
Ragazinskiene, O. et al., 2006. The influence of meteorological factors on growth and vegetation process of Perilla frutescens (L.) Britton in Lithuania. Medicina Kaunas Lithuania, 42(8), pp.667–672.
Roecklein, J.C. & Leung, P., 1987. A Profile of Economic Plants, New Brunswixk, New Jersey, USA: Transaction Publishers.
Schnitzler, Schirrmacher, W.H.G. & Grassmann, J., 2006. Perilla frutescens: A vegetable and herb for a healthy diet M. L. Chadha, G. Kuo, & C. L. L. Gowda, eds. 1st International Conference on Indigenous Vegetables and Legumes Prospectus for Fighting Poverty Hunger and Malnutrition, (752), pp.143–146.
Steckel, L. & Rhodes, N., Perilla Mint. Available at:
UMass Extension, Growing Tips 22: Annuals for the Shade. Available at:
USDA ARS, 2012. GRIN. National Genetic Resources Program. Available at: [Accessed April 2, 2012].
USDA ARS GRIN, 2013. Germplasm Resources Information Network (GRIN). Germplasm Resources Information Network, National Germplasm Resources Laboratory, Beltsville, Maryland. Available at: [Accessed March 5, 2012].
USDA ARS National Genetic Resources Program, National Germplasm Resources Laboratory, Beltsville, M., USDA ARS GRIN & USDA ARS, 2012. Taxon: Phyllostachys aurea Rivière & C. Rivière. Germplasm Resources Information Network, National Germplasm Resources Laboratory, Beltsville, Maryland. Available at: [Accessed March 5, 2012].
USDA NRCS, 2013. The PLANTS Database National Plant Data Team, ed. USDA National Plant Data Team; Available at: [Accessed December 1, 2011].
Wada, K.C., Kondo, H. & Takeno, K., 2010. Obligatory short-day plant, Perilla frutescens var. crispa can flower in response to low-intensity light stress under long-day conditions. Physiologia Plantarum, 138(3), pp.339–345.
Yu, H.-C., Kosuna, K. & Haga, M. eds., 1997. Perilla: the genus Perilla, Harwood Academic Publishers.
Zheng, H. et al., 2006. Forest Health Technology Enterprise Team Invasive Plants of Asian Origin Established in the United States and Their Natural Enemies. Biological Control, 1(March), p.160. Available at:

Perilla frutescens Photographer: John D. Byrd
Source: Mississippi State University

ppi State University


[1] Britton, N. L. & Brown, A., 1898. An illustrated flora of the northern United States: Canada and the British possessions from Newfoundland to the parallel of the southern boundary of Virginia, and from the Atlantic ocean westward to the 102d meridian, C. Scribner’s Sons.  

[2] M'Mahon, B., 1804. Seed Catalogue. in:  Special Collections of USDA ARS NAL, Beltsville, Maryland.

[3] Imlay, M., 2013. 'Spray log: Swann Park, Maryland October 1998'. personal communication with John Peter Thompson
               see also
Kobell, R., April 30, 2012. Weed warrior Marc Imlay leads the battle to conquer invading plants. Bay Journal. accessed Sept 18, 2013 ]

[4]"Weed of the Week"  Produced by the USDA Forest Service, Forest Health Staff, Newtown Square, PA. WOW 01-23-05 Invasive Plants website:

Monday, September 09, 2013

M'Mahon's "Bad Landscape Design" Description from 1806 (and today)

                              In gardening, nothing is really new. Yes, tools are invented to ease the aches and pains, and new discoveries allow us to add just the right something to make the flower grow or bloom a little longer, a little shorter, or a little more. Even our ideas about design are well-rooted in the past. Design concepts that worked in colonial America  continue to enhance our landscape enjoyment and use. The tools of the landscape design trade and the insider-tricks that are sure to get results are well founded in the historis of horticulture.

                An amazing description, for example,  of our modern suburban, cookie cutter, absent-of-any-sense-of-design developer driven landscapes was published in 1806.  Can you read this and not picture  the usual  21st century McMansion subdivision landscape or urban park installed under pressure by a developer eager to move on with maximum profit.

            "But some modern Pleasure-grounds, in which rural design is copied to an extreme, are often very barren of variety and entertainment as they frequently consist only of a grass lawn like a great field; having a running plantation of trees and shrubs all round it, just broad enough, to admit a gravel-walk winding through it, in the serpentine way, in many short twists and turns, and bordering at every turn alternately, upon the outward fence and the lawn; which are continually obtruded upon the sight, exhibiting the same prospect over and over, without the least variation; so as that after having traversed the walks all round this sort of pleasure-ground, we find no more variety or entertainment than at our first entrance, the whole having presented itself at the first view."[1]   

               If you are interested in any aspect of gardening from fruits and berries to vegetables, annuals to perennials, as well as houseplants, and are looking for an in-depth calendar of work;  and you want this to be completely organic as in no use of synthetic fertilizers or pesticides, then the work for you is The American Gardener’s Calendar by Bernard McMahon.

               M'Mahon was born in Ireland in 1775 and came to the United States in 1796 because of political instability in his native country. He settled in Philadelphia and established a seed and nursery business. Very shortly thereafter he began to collect and export seeds of American plants. Because of his work, many native American plants became established in Europe. The History of Horticulture web site continues:

"In 1804 his catalogue of seeds included 1,000 "species." He became acquainted with Thomas Jefferson as well as other distinguished men of his time. It is said that the famous Lewis and Clark expedition was planned in his home. His horticultural interests were very broad and his seed store became a meeting place for botanists and horticulturists. M'Mahon and Landreth, a noted Philadelphia nurseryman, distributed the seeds collected in the Lewis and Clark expedition. He published in 1806 the first really important horticultural book which was entitled, American Gardeners Calendar. This was a standard encyclopedia for many years. The 11th edition was published in 1857. M'Mahon was born in Ireland but came to America in 1796 because of political instability in that country. He settled in Philadelphia and established a seed and nursery business. Very shortly thereafter he began to collect and export seeds of American plants. By this means many nature plants became established in Europe. In 1804 his catalogue of seeds included 1,000 "species".

[1]  McMahon, B., 1806. The American Gardener’s Calendar; Adapted to the Climates and Seasons of the United States: Containing a Complete Account of All the Work Necessary to be Done ... for Every Month in the Year; with Ample Practical Directions for Performing the Same ..., Philadelphia, Pennsylvania: B. Graves,.

Tuesday, July 23, 2013

No complexity-stability relationship in natural communities - Cornell University Library

No complexity-stability relationship in natural communities

We performed a stability analysis of 119 quantitative food webs which were compiled using a standard methodology to build Ecopath mass-balance models. Our analysis reveals that classic descriptors of complexity do not affect stability in natural food webs. Food web structure, which is non-random in real communities, reflects another form of complexity that we found influences dramatically the stability of real communities. We conclude that the occurrence of complex communities in nature is possible owing to their trophic structure.
Comments:Main text: 9 pages, 4 figures. Supplementary Information: 14 pages, 3 figures
Subjects:Populations and Evolution (q-bio.PE)
Cite as:arXiv:1307.5364 [q-bio.PE]
 (or arXiv:1307.5364v1 [q-bio.PE] for this version)

Submission history

From: Dominique Gravel [view email]
[v1] Sat, 20 Jul 2013 01:51:27 GMT (362kb,D)

Sunday, July 14, 2013

Yokohama squash - Not Every New Plant is Invasive

Gregory Yokohama squash - USDA ARS NAL "Special Collections"

               Thomas Jefferson wrote that "the greatest service which can be rendered any country is to add an useful plant to it's culture...."[1] He could hardly imagine the unintended consequence and impact that the introduction of non indigenous species has had on the ecosystems and economies of the United States. The spread of invasive species alters ecosystem services and threaten rare and endangered species; second only to land development practices in their destructive impact. It is easy, therefore, to condemn the actions of past generations who worked hard to find new and novel species to enhance the quality of life of their fellow citizens.

               Jefferson noted that the United States were "probably far from possessing, as yet, all the articles of culture [crops] for which nature has fitted our country. To find out these, will require an abundance of unsuccessful experiments. But if, in a multitude of these, we make one or two useful acquisitions, it repays our trouble."[2] Those whom have had to fight kudzu or tamarisk might take umbrage and even be outraged at the idea that the introduced species that did not find merit were paid for.

               The US Department o Agricultural Research Service (USDA ARS) was established in part to foster Jefferson's idea that "[t]he introduction of new cultures [crops], and especially of objects [plants] of leading importance to our comfort, is certainly worthy the attention of every government, and nothing short of the actual experiment should discourage an essay of which an hope can be entertained."[3]

               Because of the significant harm of a few intentionally or accidentally introduced plants, certain stakeholders have taken a dim view to non-native plants and to those who introduced them to the United States. This tendency to lump all exotic plants into one basket is based on part on a limited view of history and the role of the men who introduced important non-native species such as wheat and vegetables. Only 150 years ago, men such as Thomas Hogg, Jr. and James J. H. Gregory worked to better the produce of our farms and gardens sure in the knowledge that they were contributing to the betterment of the country and its people.

               An 1866 article in The Cultivator & Country Gentleman provides an example of a then recent introduction of a new winter squash from Japan.

" THE YOKOHAMA SQUASH Eds Co Gent The past summer we raised Yokohama Squash and it has given such good satisfaction both as a table squash and for pies that think its merits need only to be known in order it may be appreciated The vines of this new visitor from Japan slowly till some time in July when they spread rapidly on every side taking root at almost every joint and throwing out numerous side branches so that when planted eight feet apart the entire ground is occupied by the dark green leaves while the numerous peculiar looking squashes are thickly hidden beneath them I find that they yielded with us the past season from 20 to 30 squashes to the square rod averaging four or five pounds each They are very heavy in proportion to their size the seeds being small and contained in a very small cavity The flesh is very dry sweet fine grained and of a rich orange color When cooked they make the best substitute for sweet potatoes of anything I know of and for pies I think them equal to any other squash They ripened here in Connecticut the past season but required the entire season in order to mature before frost The keep very well but 1 think not quite as well as Hubbard The stems of the Yokohama where they join the squash are nearly square a peculiarity never saw in any other squash I have no seeds spare as they are already disposed of G. F. P. Milford, Conn Feb 7 1866."[4]

William Woys Weaver (2005) describes the squash as a "oddly shaped squash that resembled large chunks of hardened lava. Gray-black, other-worldly, yet hauntingly beautiful, this unique heirloom vegetable from Japan, the ‘Yokohama’ squash, was a visual study in the Japanese affection for serenity through form and texture. [The Yokohama squash has] one of the most complex flavors I have run across in any squash or pumpkin I have grown. Everyone’s taste buds are different, but I detect hints of Asian pear, mango, avocado, lemon balsam, and if you have experience with tropical fruits, the unmistakable aroma of sapote. Can this be a squash? It is even a great boon to gardeners because it is highly resistant to borers and powdery mildew."[5]

               Who were Hogg and Gregory? Thomas Hogg, Jr. was born in London, February 6, 1820, coming to the United States with his father, Thomas Hogg, Sr. and his brother James when he was 9 months old. His father was a successful nurseryman and florist in New York City. He and his brother took over the business when their father diedin I855. A staunch liberal, progressive Republican, Thomas Hogg, Jr. was appointed U. S. Marshall in 1862 by President Lincoln, who also founded USDA and sent to Japan for eight years. He would return thereafter for two more years at a posting in the Custom House. He spent much time in travelling around the Japanese Islands studying their flora since his official position afforded him unusual facilities for exploration and collection of novel and interesting plant species and cultivars. He made a large collection of Japanese trees, shrubs and herbaceous plants "among those which proved to be adapted to our climate, are many of the choicest Japanese plants which ornament our gardens to-day, which he was the first to introduce."[6]  

               James Hogg grew the seeds sent from Japan by his brother reporting the "outcome in an 1864 issue of The Magazine of Horticulture. Hogg named the variety "Yokohama" and said it was superior to the Hubbard types which were at the time the standard in American gardens."[7] James Hogg  sent seeds of the Yokohama squash to the noted Massachusetts  plantsman, James John Howard Gregory. Mr. Gregory advertised the new squash in 1865 in Marblehead.[8]    

               I was delighted to find an original copy of the handbill advertising the Yokohama squash while compiling an inventory of pre-1870 nursery catalogs in the Special Collection of the U. S. National Agricultural Library. (USDA ARS NAL)

[1] Thomas Jefferson Memorandum of Services to My Country, after 2 September 1800  PTJ, 32:124. Polygraph copy at the Library of Congress.

[2] Letter from Thomas Jefferson to William Drayton (1786). Thomas Jefferson Agricultural Institute

[3] Letter from Thomas Jefferson to M. Lasteyrie (1808) Thomas Jefferson Agricultural Institute. (In other words, test the new crop before assuming it has nothing to offer.)

 [4] The Cultivator & Country Gentleman, Volume 27 L. Tucker & Son, 1866.

[5] Weaver. 2005. Yokohama Squash. Online. Accessed July 14, 2013.

[6] Morong, T. (1893). Thomas Hogg. Bulletin of the Torrey Botanical Club, 20(5), 217–218. doi:10.2307/2477496
Author's npte: Kudzu, which he sent to Thomas Meehan, noted nuseryman in Philadelphia in 1876, not withstanding...

[7] Baker Creek Heirloom Seed Company. Online. Accessed July 14, 2013.

[8] Shari Kelley Worrell & Norma Lovett Gregory Kelley Flude. A Timeline of his life.  Online. Accessed July 14, 2013.
Mr. Gregory purchased the rights to the "best white potato" for $150 from Luther Burbank.  Mr. Gregory introduced a new potato that he shared with Luther Burbank calling it "Burbank".