Aesculus californica (Spach) Nutt. Family - Hippocastanaceae. Common Names(s) - California buckeye. Synonym(s) - Calothyrsus californica Spach.

Answer

Score

1.01

Is the species highly domesticated?

y=-3, n=0

n

0

1.02

Has the species become naturalized where grown?

y=1, n=-1

1.03

Does the species have weedy races?

y=-1, n=-1

2.01

Species suited to tropical or subtropical climate(s) (0-low; 1-intermediate; 2-high) – If island is primarily wet habitat, then substitute “wet tropical” for “tropical or subtropical”

See Append 2

1

2.02

Quality of climate match data (0-low; 1-intermediate; 2-high) see appendix 2

2

2.03

Broad climate suitability (environmental versatility)

y=1, n=0

n

0

2.04

Native or naturalized in regions with tropical or subtropical climates

y=1, n=0

n

0

2.05

Does the species have a history of repeated introductions outside its natural range?

y=-2, ?=-1, n=0

y

-2

3.01

Naturalized beyond native range y = 1*multiplier (see Append 2), n= question 2.05

n

0

3.02

Garden/amenity/disturbance weed y = 1*multiplier (see Append 2)

n=0

n

0

3.03

Agricultural/forestry/horticultural weed y = 2*multiplier (see Append 2)

n=0

n

0

3.04

Environmental weed y = 2*multiplier (see Append 2)

n=0

n

0

3.05

Congeneric weed y = 1*multiplier (see Append 2)

n=0

y

1

4.01

Produces spines, thorns or burrs

y=1, n=0

n

0

4.02

Allelopathic

y=1, n=0

y

1

4.03

Parasitic

y=1, n=0

n

0

4.04

Unpalatable to grazing animals

y=1, n=-1

n

-1

4.05

Toxic to animals

y=1, n=0

y

1

4.06

Host for recognized pests and pathogens

y=1, n=0

y

1

4.07

Causes allergies or is otherwise toxic to humans

y=1, n=0

y

1

4.08

Creates a fire hazard in natural ecosystems

y=1, n=0

y

1

4.09

Is a shade tolerant plant at some stage of its life cycle

y=1, n=0

n

0

4.10

Tolerates a wide range of soil conditions (or limestone conditions if not a volcanic island)

y=1, n=0

y

1

4.11

Climbing or smothering growth habit

y=1, n=0

n

0

4.12

Forms dense thickets

y=1, n=0

n

0

5.01

Aquatic

y=5, n=0

n

0

5.02

Grass

y=1, n=0

n

0

5.03

Nitrogen fixing woody plant

y=1, n=0

n

0

5.04

Geophyte (herbaceous with underground storage organs -- bulbs, corms, or tubers)

y=1, n=0

n

0

6.01

Evidence of substantial reproductive failure in native habitat

y=1, n=0

n

0

6.02

Produces viable seed.

y=1, n=-1

y

1

6.03

Hybridizes naturally

y=1, n=-1

6.04

Self-compatible or apomictic

y=1, n=-1

6.05

Requires specialist pollinators

y=-1, n=0

n

0

6.06

Reproduction by vegetative fragmentation

y=1, n=-1

n

-1

6.07

Minimum generative time (years) 1 year = 1, 2 or 3 years = 0, 4+ years = -1

See left

3+

0

7.01

Propagules likely to be dispersed unintentionally (plants growing in heavily trafficked areas)

y=1, n=-1

n

-1

7.02

Propagules dispersed intentionally by people

y=1, n=-1

y

1

7.03

Propagules likely to disperse as a produce contaminant

y=1, n=-1

n

-1

7.04

Propagules adapted to wind dispersal

y=1, n=-1

n

-1

7.05

Propagules water dispersed

y=1, n=-1

y

1

7.06

Propagules bird dispersed

y=1, n=-1

n

-1

7.07

Propagules dispersed by other animals (externally)

y=1, n=-1

y

1

7.08

Propagules survive passage through the gut

y=1, n=-1

n

-1

8.01

Prolific seed production (>1000/m2)

y=1, n=-1

n

-1

8.02

Evidence that a persistent propagule bank is formed (>1 yr)

y=1, n=-1

n

-1

8.03

Well controlled by herbicides

y=-1, n=1

y

-1

8.04

Tolerates, or benefits from, mutilation, cultivation, or fire

y=1, n=-1

y

1

8.05

Effective natural enemies present locally (e.g. introduced biocontrol agents)

y=-1, n=1

Total score:

0

Notes

Source

1.01

(1)No evidence

(1)http://www.fs.fed.us/database/feis/plants/tree/aescal/all.html [Accessed 24 June 2009]

1.02

1.03

2.01

(1)Climate: California buckeye occurs in a Mediterranean climate with cool moist winters and hot dry summers [5,15,18]. The mean annual rainfall is less than 14 inches, and temperatures are in excess of 100 degrees Fahrenheit (38 degrees C) for several successive days every summer.

(1)http://www.fs.fed.us/database/feis/plants/tree/aescal/all.html [Accessed 24 June 2009]

2.02

2.03

(1)Hardiness: USDA Zone 7a: to -17.7 °C (0 °F) USDA Zone 7b: to -14.9 °C (5 °F) USDA Zone 8a: to -12.2 °C (10 °F) USDA Zone 8b: to -9.4 °C (15 °F) (2)Climate: California buckeye occurs in a Mediterranean climate with cool moist winters and hot dry summers [5,15,18]. The mean annual rainfall is less than 14 inches, and temperatures are in excess of 100 degrees Fahrenheit (38 degrees C) for several successive days every summer. (3)The California Buckeye has adapted to its native Mediterranean climate by growing during the wet winter and spring months and entering dormancy during dry summer and fall months; it begins the year's growth in early spring and begins dropping leaves by mid-summer.

(1)http://davesgarden.com/guides/pf/go/53823/ [Accessed 24 June 2009] (2)http://www.fs.fed.us/database/feis/plants/tree/aescal/all.html [Accessed 24 June 2009] (3)http://en.wikipedia.org/wiki/California_Buckeye [Accessed 25 June 2009]

2.04

(1)Climate: California buckeye occurs in a Mediterranean climate with cool moist winters and hot dry summers [5,15,18]. The mean annual rainfall is less than 14 inches, and temperatures are in excess of 100 degrees Fahrenheit (38 degrees C) for several successive days every summer. (2)No evidence

(1)http://www.fs.fed.us/database/feis/plants/tree/aescal/all.html [Accessed 24 June 2009] (2)http://www.hear.org/gcw/species/aesculus_californica/ [Accessed 25 June 2009]

2.05

(1)List of countries North America [USA] California natural [no evidence of widespread planting outside of native range] (2)Although fairly hardy throughout Britain, it grows best in areas where winter temperatures do not fall below -10°c...A moderately fast-growing and long-lived tree in the wild[229], in Britain it grows best in eastern and south-eastern England. Plants thrives at Kew [England] (3)Huntington, Arkansas...Plants I grew from seed gathered in American River canyon, CA growing well and dropping leaves in july, just like in natural CA habitat only mine are growing in Arkansas' humidity and summer rain. Have not had problems with summer water as long as drainage is good. In nature these trees usually grow on canyon slopes or just above flood level of streams. [Arkansas...outside native range] (4)Aesculus californica is a 15 to 20 foot tall deciduous tree or shrub, grown in California and Europe. It is rounded with a symmetrical branching pattern. Foliage is striking, dark green, glossy compound palmate leaves. Naturally occurs in dry canyons and gullies of California, but seems to prosper in the moist climate of England. Flowers are white to pink, fragrant, occuring on 4- to 8-inch long, 3-inch wide showy panicles. (5)In Europe, leaves persist into the fall.

(1)CAB International, 2005. Forestry Compendium. Wallingford, UK: CAB International. (2)http://www.ibiblio.org/pfaf/cgi-bin/arr_html?Aesculus+californica [Accessed 25 June 2009] (3)http://davesgarden.com/guides/pf/go/53823/ [Accessed 24 June 2009] (4)http://www.backyardgardener.com/plantname/pda_3712.html [Accessed 25 June 2009] (5)Dirr, M. 2002. Dirr's trees and shrubs for warm climates: an illustrated encyclopedia, Timber Press, Portland, OR.

3.01

(1)No evidence

(1)http://www.hear.org/gcw/species/aesculus_californica/ [Accessed 25 June 2009]

3.02

(1)[Listed as a weed but with no evidence of impacts] Darrow, R.A. Erickson, L.C. Holstrum, J.T.Jnr., Miller, J.F., Scudder, W.F. and Williams, J.L. Jnr. (1966) Report of the Terminology Committee, Standardized Names of Weeds. WSSA (14), 346-386. Weed Science Society of America. (weed)

(1)http://www.hear.org/gcw/species/aesculus_californica/ [Accessed 25 June 2009]

3.03

(1)No evidence

(1)http://www.hear.org/gcw/species/aesculus_californica/ [Accessed 25 June 2009]

3.04

(1)No evidence

(1)http://www.hear.org/gcw/species/aesculus_californica/ [Accessed 25 June 2009]

3.05

(1)Horse Chestnut - Aesculus hippocastanum L...Ecological Impacts: This species is on the Mid-Atlantic Exotic Pest Plant Council list. It has been planted as an ornamental for the attractive large white flowers and has escaped intended plantings. The weak-wooded branches break easily. The large leaves, nuts and dropping twigs create litter. Once established, this species competes with native species for sunlight, moisture and nutrients...Control and Management: • Manual- Girdle remove bark and phloem layer from 10 cm band around trunk; Note: damaging the xylem layer could encourage suckering • Chemical- Cut stems then apply herbicide; retreat suckers. Contact your state extension service. Follow label instructions and wear appropriate personal protective equipment.

(1)http://www.cirrusimage.com/tree_horse_chestnut.htm [Accessed 25 June 2009]

4.01

(1)No evidence (2)General: Buckeye Family (Hippocastanaceae). This native, deciduous shrub or tree reaches 12 m in height with a broad, rounded crown. The palmately compound leaves occur in leaflets of 5 to 7 and each leaflet is oblong-lanceolate and finely serrate. The inflorescence has many showy flowers in a panicle-like arrangement and it is erect, 1-2 dm. in length. Each individual flower has 4-5 petals and these are white to pale rose with 5-7 exserted stamens. The fruit is pear-shaped and smooth. The large, shiny light-brown seeds are 2-5 cm.

(1)Fralish, J. S. and S. B. Franklin . 2002. Taxonomy and ecology of woody plants in North American forests (excluding Mexico and subtropical Florida). John Wiley and Sons. (2)http://plants.usda.gov/plantguide/pdf/cs_aeca.pdf [Accessed 24 June 2009]

4.02

(1)California bay and California buckeye are species that have known allopathic effects on other organisms. Plant growth is sparse under bay trees and buckeye seeds have been known to stupefy fish and retard the growth of competing plants. These two plants were chosen to make the herbicides in an attempt to formulate an organic herbicide to replace Roundup that is being sprayed at our school. The data on the leaf spray treatments showed the established plants changing in color from a healthy green to a definitive dead (crispy) brown one week after treatment with the 100% buckeye extract and the same results with the 100% bay extract 9 days after the initial treatment. The 50% extracts had similar effects on the established grass but with an increased time span to kill the grass. The soil treatments, had some effect in the four trials in that it took one day longer for the seeds to germinate in the treated soil and the grass at about a 20% slower growth rate. We want to continue to work with these extracts in a more uncontrolled environment in the coming year. (2)We tested 55 plant species in northern California for water-extractable and volatile inhibitors of plant growth with seed bioassays: 69% significantly inhibited, and none significantly stimulated, radicle growth of Hordeum vulgare when tested as 1:25 or 1:50 (g tissue:ml water) extracts, whereas 38% inhibited and 15% stimulated Bromus mollis. Extracts of species in the Compositae and Labiatae, as well as Aesculus californica, Ailanthus altissima, Brassica nigra, Ceanothus integerrimus, Lupinus arboreus, Nicotiana glauca, Ribes cereum, and Scrophularia californica, were the most inhibitory. Only Artemisia tridentata, Heteromeles arbutifolia, Salvia sonomensis, and Trichostema lanceolatum released strongly inhibitory volatiles; T. lanceolatum was clearly the most toxic species tested, its extracts and volatiles greatly suppressing growth of the indicators. Five of the species most inhibitory in the initial screening were selected for further investigation Their extracts reduced germination and growth of a number of northern California plants, but when the extracts were inoculated with 0.5 g soil and incubated several months at room temperature, most gradually diminished in toxicity

(1)Jimenez, I. and J. Woods. 2004. The Alleopathic Effects of Extracts from Umbellularia californica and Aesculus californica on the Grass Lolium perenne. CALIFORNIA STATE SCIENCE FAIR 2004 PROJECT SUMMARY. Available from http://www.usc.edu/CSSF/History/2004/Projects/J1412.pdf [Accessed 25 June 2009] (2)Heisey, R. M. and C. C. Delwiche. 1983. A Survey of California Plants for Water-Extractable and Volatile Inhibitors. Botanical Gazette 144(3): 382-390 .

4.03

(1)This native, deciduous shrub or tree reaches 12 m in height with a broad, rounded crown [no evidence].

(1)http://plants.usda.gov/plantguide/pdf/cs_aeca.pdf [Accessed 24 June 2009]

4.04

(1)Despite its toxicity, California buckeye flowers, leaves, and shoots are palatable to livestock and wildlife. Hedrick [14] has listed it among the 20 chaparral browse plants most preferred by cattle and black-tailed deer.

(1)http://www.fs.fed.us/database/feis/plants/tree/aescal/all.html [Accessed 24 June 2009]

4.05

(1)California buckeye is toxic to all classes of livestock and wildlife. The bark, leaves, stems, fruits, and seeds all contain glycosidal compounds which cause haemolytic action on red blood cells and depress the central nervous system when ingested. This species has been implicated in inducing abortion in cattle [5,18].

(1)http://www.fs.fed.us/database/feis/plants/tree/aescal/all.html [Accessed 24 June 2009]

4.06

(1)Pests recorded:
Fungus diseases:
Phytophthora ramorum (sudden oak death syndrome (SODS))
Pests recorded at the generic level (Aesculus):
Insects:
Chaetocnema confinis (flea beetle)
Cossus cossus (carpenter moth)
Diaspidiotus ostreaeformis (pear oyster scale)
Diaspidiotus perniciosus (San José scale)
Popillia japonica (Japanese beetle)
Pseudaulacaspis pentagona (mulberry scale)
Rosellinia necatrix (dematophora root rot)
Scolytus intricatus (European oak bark beetle)
Zeuzera pyrina (moth, wood leopard)
Fungus diseases:
Apiognomonia errabunda (anthracnose)
Nectria galligena (Nectria canker (apple, pear))
Bacterial diseases:
Rhizobium radiobacter (crown gall)
Rhizobium rhizogenes (gall)

(1)CAB International, 2005. Forestry Compendium. Wallingford, UK: CAB International.

4.07

(1)All parts of the plant are poisonous to people. The seeds were ground up and used by Native Americans to stun fish. The flowers have also been reported to be poisonous to bees.

(1)Quinn, R. D., S. C. Keeley, and M. D. Wallace. 2006. Introduction to California chaparral. University of California Press, Berkeley and Los Angeles, CA.

4.08

(1)Fire ecology: Early leaf fall results in accumulation of dry litter around the plant early in the fire season...Seeds would probably not survive fire because they are highly susceptible to desiccation by heat...Information regarding California buckeye's response to fire is limited. Sampson [25] has said that sprouting chaparral brush species, including California buckeye, recover rapidly following a fire, sending out new shoots during the first growing season. Growth in subsequent seasons is also rapid, with the plant sometimes exceeding its prefire mass within a few years. Sprouting can occur within a few weeks following fire, even in the summer months. Growth is supported by drawing on food and water reserves in the fully developed root system.

(1)http://www.fs.fed.us/database/feis/plants/tree/aescal/all.html [Accessed 24 June 2009]

4.09

(1)Native to the central coast ranges and Sierra Nevada mountains in partial shade to full sun, (2)Sun Exposure: Sun to Partial Shade (3)Light Requirement: Sun , Part Shade (4)It cannot grow in the shade...Requires a position in full sun[200]. Prefers dry sunny locations

(1)http://www.laspilitas.com/nature-of-california/plants/aesculus-californica [Accessed 24 June 2009] (2)http://davesgarden.com/guides/pf/go/53823/ [Accessed 24 June 2009] (3)http://www.wildflower.org/plants/result.php?id_plant=AECA [Accessed 24 June 2009] (4)http://www.ibiblio.org/pfaf/cgi-bin/arr_html?Aesculus+californica [Accessed 25 June 2009]

4.10

(1)Soil pH requirements: 6.6 to 7.5 (neutral) 7.6 to 7.8 (mildly alkaline) 7.9 to 8.5 (alkaline) (2)Soil Description: Poor, dry soils. (3)Soil: California buckeye grows in sandy, sandy-loam, or gravelly-loam soils (4)Prefers a deep loamy well-drained soil but is not too fussy

(1)http://davesgarden.com/guides/pf/go/53823/ [Accessed 24 June 2009] (2)http://www.wildflower.org/plants/result.php?id_plant=AECA [Accessed 24 June 2009] (3)http://www.fs.fed.us/database/feis/plants/tree/aescal/all.html [Accessed 24 June 2009] (4)http://www.ibiblio.org/pfaf/cgi-bin/arr_html?Aesculus+californica [Accessed 25 June 2009]

4.11

(1)This native, deciduous shrub or tree reaches 12 m in height with a broad, rounded crown.

(1)http://plants.usda.gov/plantguide/pdf/cs_aeca.pdf [Accessed 24 June 2009]

4.12

(1)A somewhat shorter, more spreading deciduous tree, Aesculus californica, occurs as scattered individuals or in small clumps. [no evidence that this plant excludes other vegetation] (2)California buckeye exhibits both tolerant and intolerant characteristics. It occurs as a widely scattered individuals in open grasslands. It also occurs as an understory shrub in mixed evergreen forest [3]. It is a climax indicator in chaparral and mixed oak communities [1] and in California buckeye woodlands [8].

(1)Barbour, M. G. and W. D. Billings. 2000. North American terrestrial vegetation. Cambridge University Press, Cambridge, UK. (2)http://www.fs.fed.us/database/feis/plants/tree/aescal/all.html [Accessed 24 June 2009]

5.01

(1)Terrestrial

(1)Barbour, M. G. and W. D. Billings. 2000. North American terrestrial vegetation. Cambridge University Press, Cambridge, UK.

5.02

(1)Hippocastanaceae

(1)Barbour, M. G. and W. D. Billings. 2000. North American terrestrial vegetation. Cambridge University Press, Cambridge, UK.

5.03

(1)Hippocastanaceae

(1)Barbour, M. G. and W. D. Billings. 2000. North American terrestrial vegetation. Cambridge University Press, Cambridge, UK.

5.04

(1)This native, deciduous shrub or tree reaches 12 m in height with a broad, rounded crown.

(1)http://plants.usda.gov/plantguide/pdf/cs_aeca.pdf [Accessed 24 June 2009]

6.01

(1)No evidence

(1)Barbour, M. G. and W. D. Billings. 2000. North American terrestrial vegetation. Cambridge University Press, Cambridge, UK.

6.02

(1)The fruit is pear-shaped and smooth. The large, shiny light-brown seeds are 2-5 cm...Harvest the large seeds from the tree or shrub about November. Plant them in the ground immediately--half buried in an area of full sun or light shade.

(1)http://plants.usda.gov/plantguide/pdf/cs_aeca.pdf [Accessed 24 June 2009]

6.03

(1)Abstract: Evidence from morphology, distribution patterns, allozyme variation, and meiotic irregularities associated with decreased pollen germinability confirms the existence of a broad hybrid zone involving three parapatric species of Aesculus in the southeastern United States. The overall hybrid zone involving the three species is at least 200 km in width and probably represents the overlap of two hybrid zones: one between A. pavia and A. sylvatica and the other between A. flava and A. sylvatica. Both zones are highly asymmetrical, with hybrid populations occurring primarily in the Piedmont, where A. sylvatica is native. Detailed analyses of the hybrid zone involving A. pavia and A. sylvatica showed that hybrid populations consistently lack one or both of the putative parental species. Morphology and allozyme variation provide similar estimates of the position of the hybrid zone, but allozymes allow the detection of a larger zone than apparent on the basis of morphology. All available evidence is consistent with the hypothesis that extensive introgression has occurred among these species. Nevertheless, allozymic differentiation between these species is insufficient to reject hypotheses other than introgression that could generate the genetic structure observed in hybrid populations. Observations of pollinator activity in populations of A. pavia, A. sylvatica, A. flava, and their hybrids showed that these species share a number of important pollinators, including several species of bumblebees (Bombus) and the ruby-throated hummingbird (Archilochus colubris). Spring migration patterns of the ruby-throated hummingbird coincide closely with the flowering phenology of each of the Aesculus species, suggesting that hummingbirds could be vectors of long-distance pollen dispersal. The lifespan of pollen under field conditions is sufficient to permit transport of pollen in this fashion over distances of tens or hundreds of kilometers. Directional migration and arrival of hummingbirds after peak flowering would enforce a directional pattern of gene flow and could generate an asymmetrical hybrid zone of unusually great width. [hybridization occurs within genus, but unknown if A. californica forms natural hybrids with other species]

(1)dePamphilis, C. W. and R. Wyatt. 1989. Hybridization and Introgression in Buckeyes (Aesculus: Hippocastanaceae): A Review of the Evidence and a Hypothesis to Explain Long-Distance Gene Flow. Systematic Botany 14(4): 593-611 .

6.04

(1)The scented flowers are hermaphrodite (have both male and female organs) and are pollinated by Bees. [unknown if able to self-compatible]

(1)http://www.ibiblio.org/pfaf/cgi-bin/arr_html?Aesculus+californica [Accessed 25 June 2009]

6.05

(1)Apian considerations: Honeybees are the chief pollinators of California buckeye, but the pollen and nectar are toxic to them. (2)The flowers are toxic to European honeybees (Apis mellifera); however, native pollinators relish the collection of nectar without side effects. The adult pale swallowtail butterfly (Papilio eurymedon) appears particularly fond of this plant.

(1)http://www.fs.fed.us/database/feis/plants/tree/aescal/all.html [Accessed 24 June 2009] (2)Callahan, F. 2005. PLANT OF THE YEAR California Buckeye (Aesculus californica (Spach) Nutt.). Kalmiopsis Volume 12: 9-15.

6.06

(1)Propagation Methods: From seed; direct sow outdoors in fall From seed; stratify if sowing indoors From seed; direct sow after last frost [no evidence]

(1)http://davesgarden.com/guides/pf/go/53823/ [Accessed 24 June 2009]

6.07

(1)A moderately fast-growing and long-lived tree in the wild (2)This is only for young people to plant. It grows extremely slow. (3)It has a moderate growth rate and a height of 40 feet at maturity. [probably flowers in >3-4 years]

(1)http://www.ibiblio.org/pfaf/cgi-bin/arr_html?Aesculus+californica [Accessed 25 June 2009] (2)http://davesgarden.com/guides/pf/go/53823/ [Accessed 24 June 2009] (3)http://plants.sagebud.com/california-buckeye-aesculus-californica/ [Accessed 25 June 2009]

7.01

(1)The fruit is pear-shaped and smooth. The large, shiny light-brown seeds are 2-5 cm. [no means of external attachment]

(1)http://plants.usda.gov/plantguide/pdf/cs_aeca.pdf [Accessed 24 June 2009]

7.02

(1)Ornamental

(1)Dirr, M. 2002. Dirr's trees and shrubs for warm climates: an illustrated encyclopedia, Timber Press, Portland, OR.

7.03

(1)The fruit is pear-shaped and smooth. The large, shiny light-brown seeds are 2-5 cm. [no evidence, and unlikely with such large seeds]

(1)http://plants.usda.gov/plantguide/pdf/cs_aeca.pdf [Accessed 24 June 2009]

7.04

(1)The fruit is pear-shaped and smooth. The large, shiny light-brown seeds are 2-5 cm.

(1)http://plants.usda.gov/plantguide/pdf/cs_aeca.pdf [Accessed 24 June 2009]

7.05

(1)Seed dispersal is poor and is accomplished mainly by gravity or water; dispersal by animals is rare.

(1)http://www.fs.fed.us/database/feis/plants/tree/aescal/all.html [Accessed 24 June 2009]

7.06

(1)Wildlife: Do not plant buckeyes near apiaries as the flowers are poisonous to honey bees. No wildlife eat buckeye seeds except squirrels, such as the California ground squirrel (Citellus beecheyi). [not fleshy fruited] (2)The palatability of the seeds for black-tailed deer, rodents, and Stellar's jay is fair to poor [birds and other animals are seed predators]

(1)http://plants.usda.gov/plantguide/pdf/cs_aeca.pdf [Accessed 24 June 2009] (2)http://www.fs.fed.us/database/feis/plants/tree/aescal/all.html [Accessed 24 June 2009]

7.07

(1)Wildlife: Do not plant buckeyes near apiaries as the flowers are poisonous to honey bees. No wildlife eat buckeye seeds except squirrels, such as the California ground squirrel (Citellus beecheyi). [seed predators, but squirrels and rodents may disperse seeds by storing them for later consumption] (2)Squirrels will selectively eat parts of the seeds. They bury others which can sprout like acorns.

(1)http://plants.usda.gov/plantguide/pdf/cs_aeca.pdf [Accessed 24 June 2009] (2)http://davesgarden.com/guides/pf/go/53823/ [Accessed 24 June 2009]

7.08

(1)Seed dispersal is poor and is accomplished mainly by gravity or water; dispersal by animals is rare. (2)Wildlife: Do not plant buckeyes near apiaries as the flowers are poisonous to honey bees. No wildlife eat buckeye seeds except squirrels, such as the California ground squirrel (Citellus beecheyi). [animal consumption of seeds likely results in predation, and not internal dispersal]

(1)http://www.fs.fed.us/database/feis/plants/tree/aescal/all.html [Accessed 24 June 2009] (2)http://plants.usda.gov/plantguide/pdf/cs_aeca.pdf [Accessed 24 June 2009]

8.01

(1)California buckeye reproduces by seed [5]. The average tree produces approximately 100 seeds per year.

(1)http://www.fs.fed.us/database/feis/plants/tree/aescal/all.html [Accessed 24 June 2009]

8.02

(1)Description: Fall-sown seeds germinate easily without pretreatment. Seed Collection: Seeds dry and shrivel quickly. (2)Seeds are viable for only 1 year and are shed from November to mid-February (3)The seed has a very limited viability and must not be allowed to dry out. Stored seed should be soaked for 24 hours prior to sowing and even after this may still not be viable

(1)http://www.wildflower.org/plants/result.php?id_plant=AECA [Accessed 24 June 2009] (2)http://www.fs.fed.us/database/feis/plants/tree/aescal/all.html [Accessed 24 June 2009] (3)http://www.ibiblio.org/pfaf/cgi-bin/arr_html?Aesculus+californica [Accessed 25 June 2009]

8.03

(1)Control treatments: California buckeye is susceptible to spray or injection/cut surface treatments of phenoxy herbicides and picloram [7,14,27]. Hand or mechanical brush control is ineffective unless the root crown is removed [25,28].

(1)http://www.fs.fed.us/database/feis/plants/tree/aescal/all.html [Accessed 24 June 2009]

8.04

(1)Asexual: California buckeye can sprout from the stump or root crown...Plant adaptations: California buckeye sprouts from the root crown after aboveground portions of the plant have been damaged [5,28]. Seeds would probably not survive fire because they are highly susceptible to desiccation by heat...Information regarding California buckeye's response to fire is limited. Sampson [25] has said that sprouting chaparral brush species, including California buckeye, recover rapidly following a fire, sending out new shoots during the first growing season. Growth in subsequent seasons is also rapid, with the plant sometimes exceeding its prefire mass within a few years. Sprouting can occur within a few weeks following fire, even in the summer months. Growth is supported by drawing on food and water reserves in the fully developed root system [20].

(1)http://www.fs.fed.us/database/feis/plants/tree/aescal/all.html [Accessed 24 June 2009]

8.05

Unknown