Pacific Island Ecosystems at Risk (PIER)


Camellia sinensis


RISK ASSESSMENT RESULTS: Low risk, score: -4


Australian/New Zealand Weed Risk Assessment adapted for Hawai‘i.
Information on Risk Assessments
Original risk assessment

Camellia sinensis (L.) Kuntze Family - Theaceae. Common names - tea, black tea, green tea, cha. Synonyms - Camellia assamica (Mast.) Hung T. Chang [= Camellia sinensis var. assamica], Camellia oleosa (Lour.) Rehder [= Camellia sinensis forma parvifolia], Camellia thea Link [= Camellia sinensis var. sinensis], (previously associated with 2 accessions), Camellia theifera Griff. [= Camellia sinensis var. assamica] (previously associated with 2 accessions), Thea bohea L., Thea oleosa Lour. [= Camellia sinensis var. sinensis], Thea sinensis L. [≡ Camellia sinensis var. sinensis] (previously associated with 18 accessions) Thea viridis L. (previously associated with 15 accessions)

Answer

Score

1.01

Is the species highly domesticated?

n

0

1.02

Has the species become naturalized where grown?

1.03

Does the species have weedy races?

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”

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

2.04

Native or naturalized in regions with tropical or subtropical climates

y

1

2.05

Does the species have a history of repeated introductions outside its natural range? y=-2

y

3.01

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

y

1

3.02

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

n

0

3.03

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

n

0

3.04

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

n

0

3.05

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

n

0

4.01

Produces spines, thorns or burrs

n

0

4.02

Allelopathic

4.03

Parasitic

n

0

4.04

Unpalatable to grazing animals

y

1

4.05

Toxic to animals

n

0

4.06

Host for recognized pests and pathogens

y

1

4.07

Causes allergies or is otherwise toxic to humans

n

0

4.08

Creates a fire hazard in natural ecosystems

n

0

4.09

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

y

1

4.1

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

n

0

4.11

Climbing or smothering growth habit

n

0

4.12

Forms dense thickets

n

0

5.01

Aquatic

n

0

5.02

Grass

n

0

5.03

Nitrogen fixing woody plant

n

0

5.04

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

n

0

6.01

Evidence of substantial reproductive failure in native habitat

n

0

6.02

Produces viable seed.

y

1

6.03

Hybridizes naturally

6.04

Self-compatible or apomictic

n

-1

6.05

Requires specialist pollinators

n

0

6.06

Reproduction by vegetative fragmentation

n

-1

6.07

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

4

-1

7.01

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

n

-1

7.02

Propagules dispersed intentionally by people

y

1

7.03

Propagules likely to disperse as a produce contaminant

n

-1

7.04

Propagules adapted to wind dispersal

n

-1

7.05

Propagules water dispersed

n

-1

7.06

Propagules bird dispersed

n

-1

7.07

Propagules dispersed by other animals (externally)

n

-1

7.08

Propagules survive passage through the gut

n

-1

8.01

Prolific seed production (>1000/m2)

n

-1

8.02

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

n

-1

8.03

Well controlled by herbicides

8.04

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

8.05

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

Total score:

-4

Supporting data:

Notes

Reference

1.01

"The Chinese have enjoyed tea for centuries, if not millennia. While historically the use of tea as a medicinal herb useful for staying awake is unclear, China is considered to have the earliest records of tea drinking, with recorded tea use in its history dating back to the first millennium BC. The Han Dynasty used tea as medicine." [No evidence that the cultivated tea is ecologically different from the wild tea.]

http://en.wikipedia.org/wiki/Tea

1.02

1.03

2.01

(1)"Native:
ASIA-TEMPERATE
China: China - Guangdong, Guangxi, Yunnan [s.]
ASIA-TROPICAL
Indian Subcontinent: India - Assam; Indo-China: Indochina; Myanmar [n.]; Thailand [n.]" (2)"Native to Southeast Asia, from Sri Lanka and India to Assam and China, tea has been planted widely in tropical and subtropical areas. Near the Equator, it ranges up to nearly 2,000 m elevation."

(1)http://www.ars-grin.gov/cgi-bin/npgs/html/tax_search.pl (2)http://www.hort.purdue.edu/newcrop/duke_energy/Camellia_sinensis.html

2.02

(1)Native to Southeast Asia, from Sri Lanka and India to Assam and China, tea has been planted widely in tropical and subtropical areas. Near the Equator, it ranges up to nearly 2,000 m elevation."

(1)http://www.hort.purdue.edu/newcrop/duke_energy/Camellia_sinensis.html

2.03

(1)"can be grown outside in zones 7-9." (2)"Hardiness: USDA Zone 11." (3)"Many high quality tea plants grow at elevations up to 5,000 feet (1524 meters), as the plants grow more slowly and acquire a better flavor." … "Near the Equator, it ranges up to nearly 2,000 m elevation. " (4)"USDA: 7b-11"

(1)http://www.plantoftheweek.org/week046.shtml (2)http://davesgarden.com/pf/go/57841/ (3)http://en.wikipedia.org/wiki/Tea (4)http://www.desert-tropicals.com/Plants/Theaceae/Camellia_sinensis.html

2.04

(1)"Native:
ASIA-TEMPERATE
China: China - Guangdong, Guangxi, Yunnan [s.]
ASIA-TROPICAL
Indian Subcontinent: India - Assam; Indo-China: Indochina; Myanmar [n.]; Thailand [n.]" (2)"Native to Southeast Asia, from Sri Lanka and India to Assam and China, tea has been planted widely in tropical and subtropical areas. Near the Equator, it ranges up to nearly 2,000 m elevation."

(1)http://www.ars-grin.gov/cgi-bin/npgs/html/tax_search.pl (2)http://www.hort.purdue.edu/newcrop/duke_energy/Camellia_sinensis.html

2.05

(1)widely cultivated v(2)"Native to Southeast Asia, from Sri Lanka and India to Assam and China, tea has been planted widely in tropical and subtropical areas. Near the Equator, it ranges up to nearly 2,000 m elevation."

(1)http://www.ars-grin.gov/cgi-bin/npgs/html/tax_search.pl (2)http://www.hort.purdue.edu/newcrop/duke_energy/Camellia_sinensis.html

3.01

(1)"Camellia sinensis (L.) Kuntze. New island record. Tea has been cultivated in the Hawaiian Islands for over a century, experimentally as a commercial crop and as a home garden ornamental. Lorence & Flynn (this issue) record-ed the first record of it being naturalized in the state (on Kaua‘i). The record below marks the first naturalized record of C. sinensis on the island of Hawai‘i. In Hauani Gulch C.sinensis is a dominant middle-story tree, with abundant plants present in all size classes."

(1)http://72.14.253.104/search?q=cache:BFpYh6ldXUMJ:hbs.bishopmuseum.org
/pdf/op88-6.pdf+%22Camellia+sinensis%22+naturalized%7C
naturalizing%7Cnaturalize&hl=en&ct=clnk&cd=3&gl=us

3.02

No evidence

3.03

No evidence

3.04

No evidence

3.05

No evidence

4.01

No evidence

4.02

(1)"Abstract: Laboratory and greenhouse experiments were conducted to determine the effects of tea (Camellia sinensis (L.) Kuntze) extracts (leaf, flower and fruit) at different concentrations on germination and growth of garden cress (Lepidium sativum L.), lettuce (Lactuca sativa L.), redroot pigweed (Amaranthus retroflexus L.) and golden foxtail (Setaria glauca (L.) P.Beauv.). Furthermore, the effects of dried residues of tea on leaf area and dry weight of redroot pigweed and golden foxtail were investigated. Concentrations ranged from 0, 2.5, 5 to 10 % for organ extracts and dried residues were tested in mixtures with perlite at rates of 0, 8, 16, 24 and 32 g kg(-1). Polyethylene glycole (PEG) was used in order to distinguish between the inhibitory effect of possible allelopathic substances and effects caused by the osmotic potential of the extracts. Results showed that garden cress and redroot pigweed germination was reduced by all extracts of tea organs with the exception of the leaf extract at the lowest concentration. ..." [No evidence of allelopathy under field conditions].

(1)Rezaeinodehi, A.; Khangholi, S.; Aminidehaghi, M., et al.
Allelopathic potential of tea (Camellia sinensis (L.) Kuntze) on germination and growth of Amaranthus retroflexus L. and Setaria glauca (L.) P. Beauv.
Journal of Plant Diseases and Protection (Sp. Iss. 20) : 447-454 2006.

4.03

No evidence.

4.04

is not suitable for fodder

http://www.hort.purdue.edu/newcrop/duke_energy/Camellia_sinensis.html

4.05

No evidence

4.06

(1)"Numerous fungi attack the tea plant, including the following: Aglaospora aculeata, Amphitiarospora neothiosporoides, Armillaria mellea, Asterina camelliae, Auricularia polytricha, Beltrania indica, Botryodiplodia theobromae, Botryosphaeria microspora, B. ribis, B. theicola, Calonectria theae, Cephaleuros virescens, C. mycoidea, Cercospora theae, Colletotrichum camelliae, Corticium salmonicolor, C. solani, Cylindrocladium camelliae, C. parvum, Diatrype conferta, Didymosphaeria theae, Discosiella longiciliata, Elsinoe theae, Exobasidium vexans, Fomes lignosus, F. noxius, Fusarium oxysporum, Glomerella cingulata, Guignardia camelliae, Helicobasidium compactum, Hypocrella scutata, Hypoxylon michelianum, H. vestitum, Irpex destruens, Leptoporum lignosus, Leptosphaeria depressa, L. tornatospora, Macrophoma theae, M. theicola, Macrophomina phaseoli, Marasmius equicrinus, M. pulcher, M. scandens, Massaria theicola, Melanoconiella stellata, Mycosphaerella camelliae, M. ikedai, M. theae, Nectria lucida, Penicillium caryophilum, Pestalotia theae, P. guepini, Pestalotiopsis gigas, P. nattrassii, P. theae, Phaeosphaerella theae, Phoma camelliae, Phyllosticta erratica, Ph. theae, Pythium complectens, P. vexans, Rhizoctonia bataticola, Rosellina arcuata, R. bunodes, Sclerotium rolfsii, S. zeylanicum, Sphaerostilbe repens, Sporidesmium deightonii, S. tropicale, Stachylidium bicolor, Stilbella theae, Thyronectria pseudotrichia, Trichoderma viridi, Ustulina deusta and U. zonata. Bacteria known to attack tea include: Agrobacterium tumefaciens, Erwinia theae and Pseudomonas theae. The cause of oil-spot is undetermined. Many nematodes are known to infest tea also, including: Anguillulina pratensis, Basirotyleptus archius, B. basiri, B. eximius, Criconema octangulare, Criconemella. rustica, Helicotylenchus erythrinae, Hemicriconemoides brachyurus, H. gaddi, H. kanayaensis, Hemicycliophora longicaudata, Longidorus utriculoides, Meloidogyne arenaria, M. brevicauda, M. camelliae, M. hapla, M. incognita, M. incognita acrita, M. javanica, Paratylenchus curvitatus, Pratylenchus coffeae, P. loosi, P. pratensis, Radopholus similes, Trichodorus monohystera, Xiphanema campinense, X. radicicola." (2)Phytophthora ramorum, commonly known as Sudden Oak Death

(1)http://www.hort.purdue.edu/newcrop/duke_energy/Camellia_sinensis.html (2)http://agr.mt.gov/news/pr2004/prQuarantine3-04.asp

4.07

Probably not - The toxicity records found pertained to extracts from C. sinensis and not the actual plant material.

4.08

Probably not - "Camellia sinensis is an evergreen plant and grows in tropical to sub-tropical climates." [Also no evidence of this otherwise cultivated species naturalizing in the form of thickets].

http://en.wikipedia.org/wiki/Tea

4.09

(1)"At first, seedlings should be shaded." (2)"Camellia sinensis need full sun to part shade." (3)"Sun Exposure: Full Sun. Sun to Partial Shade."

(1)http://www.hort.purdue.edu/newcrop/duke_energy/Camellia_sinensis.html (2)http://www.plantoftheweek.org/week046.shtml (3)http://davesgarden.com/pf/go/57841/

4.1

(1)pH of 4.5 to 7.3. Thrives on tropical red earths and deep, well-drained, acid (pH 4.5-6.0) soils. (2)The Tea bush prefers an acid soil rich in organic matter. [Probably not -the pH range is acidic to neutral and not alkaline].

(1)http://www.hort.purdue.edu/newcrop/duke_energy/Camellia_sinensis.html (2)http://www.desert-tropicals.com/Plants/Theaceae/Camellia_sinensis.html

4.11

No evidence.

4.12

No evidence

5.01

(1)"Tea plants will grow into a tree if left undisturbed but cultivated plants are pruned to waist height for ease of plucking." (2)"Small evergreen tree to 16 m tall, usually pruned back to shrubs in cultivation."

(1)http://en.wikipedia.org/wiki/Tea (2)http://www.hort.purdue.edu/newcrop/duke_energy/Camellia_sinensis.html

5.02

5.03

5.04

6.01

No evidence.

6.02

"Tea is propagated either from seeds or by vegetative means."

http://www.hort.purdue.edu/newcrop/duke_energy/Camellia_sinensis.html

6.03

"Abstract: In order to introduce the favorable characteristics of Camellia japonica L., such as disease resistance and cold hardiness to tea plants (Camellia sinensis (L) O. KUNTZE), interspecific hybrids between C. sinensis and C. japonica were bred, and their morphological and physiological characteristics as well as suitability for the manufactured of green tea were investigated. 1. Of the 300 crosses made in 1979 using C. sinensis as the seed parent and C. japonica as the pollen parent, 9 hybrids were obtained out of 16 seeds from 13 fruits in 1980. 2. F1 plants between C. sinensis and C. japonica were all diploids with 2n = 30, like both parents. 3. The form of the leaves and flowers of the F1 plants was generally intermediate between that of both parents. 4. F1 plants flowered in autumn, from October to December, like C. sinensis and their flowers were red-pink and paler than those of C. japonica used as pollen parent. The pollen fertility of the F1 plants was about 20 to 45 percent lower, and giant pollen was often observed. 5. All of the F1 plants showed a high disease resistance to tea gray blight (Pestalotia longiseta) and to tea anthracnose (Gloeosporium theae-sinensis) which are the most important diseases of tea plant in Japan. Moreover, they were very resistant to cold damage in winter. Both their disease resistance and cold hardiness were equivalent to those of the strongest tea cultivars. 6. Among the chemical components of the F1 plants, the caffeine content in the new shoots of the 1st crop was only 10 percent and the catechin content in mature leaves in winter was 20 to 40 percent of that of the tea plant used as seed parent, respectively. Amino acid concentrations showed appreciable differences among the F1 plants which contained all the kinds of amino acids present in tea leaves. 7. As for the cup quality for green tea of the F1 plants, since the taste was generally insipid and acid, it was doubtful that these plants could be used directly as tea cultivars. However, it is considered that the plants could be useful as the promising parental plant for the development of varieties resistant to diseases and cold weather in tea breeding. 8. Based on the observations of the morphological and physiological characteristics, since it was confirmed that the F1 plants obtained in this experiment were true hybrids between C. sinensis and C. japonica, they were named 'Chatsubaki'."
[No evidence of natural hybrids].

TAKEDA Y; YANASE Y; AMMA S
BREEDING OF INTERSPECIFIC HYBRIDS BETWEEN CAMELLIA-SINENSIS L O. KUNTZE AND CAMELLIA-JAPONICA L. AND THEIR CHARACTERISTICS
Bulletin of the National Research Institute of Vegetables Ornamental Plants and Tea Series B (1) : 11-22 1987

6.04

"Tea flowers are largely, if not completely, self-sterile and require cross-pollination by insects to produce seed."

http://www.hort.purdue.edu/newcrop/duke_energy/Camellia_sinensis.html

6.05

Probably not - "Tea flowers are largely, if not completely, self-sterile and require cross-pollination by insects to produce seed."

http://www.hort.purdue.edu/newcrop/duke_energy/Camellia_sinensis.html

6.06

No evidence of spread by vegetative means.

6.07

"It requires 4-12 years to bear seed. "

http://www.hort.purdue.edu/newcrop/duke_energy/Camellia_sinensis.html

7.01

No evidence of the species growing in heavily trafficked areas.

7.02

"Dried and cured leaves widely used for a beverage, which has a stimulant effect due to caffeine."

http://www.hort.purdue.edu/newcrop/duke_energy/Camellia_sinensis.html

7.03

Probably not - no evidence that the species grows near fields of seed crops.

7.04

Probably not - no evidence that the propagules have any adaptation for wind dispersal.

7.05

Probably not - no evidence that the species grows in or around waterways.

7.06

Photo of seed bearing fruits does not suggest dispersal by birds.

http://images.google.com/images?
svnum=10&um=1&hl=en&rls=DIUS%2CDIUS%3A2006-15%2CDIUS%3Aen&q=%22Camellia+sinensis%22++fruits

7.07

Probably not - no evidence that the propagules have any means of dispersal.

7.08

Probably not - no evidence of ingestion.

8.01

(1)"capsules depressed-globose, brownish, lobate, to 2 cm broad, valvate, with 1-3 subglobose seeds in each lobe; approximately 500 seeds per kg." (2)Photo of seeds [Probably not - relatively large seeds]

(1)http://www.hort.purdue.edu/newcrop/duke_energy/Camellia_sinensis.html (2)http://images.google.com/imgres?imgurl=
http://blog.taiwan-guide.org/wp-content/uploads/tea-seeds.jpg
&imgrefurl=http://blog.taiwan-guide.org/2007/01/the-art-of-making-tea-oil/&h=330
&w=440&sz=45&hl=en&start=2&um=1&tbnid=maY_8VA4iUl8JM:&tbnh=95
&tbnw=127&prev=/images%3Fq%3D%2522Camellia%2Bsinensis%2522%2B
%2Bseeds%26svnum%3D10%26um%3D1%26hl%3Den%26rls%3DDIUS,DIUS:2006-15,DIUS:en%26sa%3DG

8.02

"Abstract: Tea (Camellia sinensis L.) seed exhibits recalcitrant behavior and is short-lived. The effect of various moist sand (water/chemical) preconditioning treatments was studied to extend viability of tea seed. The best treatment was moist sand incubation with PEG maintaining -5 bar water potential and containing 0.05% mercuric chloride; closely followed by water or PEG with 0.25% of Dithane M-45. The vigour of surviving seedlings as measured by root and shoot growth was also better in these treatments than in the untreated control. The percentage of cracked and sprouted seeds could be reduced substantially with the proper maintenance of requisite moisture level of sand media in storage." [Probably not - recalcitrant seeds]

Bhattacharya, A. K.; Rahman, F.; Basu, R. N.

Preservation of tea (Camellia sinensis L.) seed viability

Seed Research (New Delhi) 22 (2) : 108-111 1994 (1996)

8.03

No evidence that the species is being controlled for.

8.04

(1)"The Camellia sinensis plant is a small shrub about 1-2 meters in height, though it will grow taller if you don't prune it." (2)"Abstract - Root–shoot interaction in the tea plant, in relation to turnover of root reserves, following pruning and manuring, were investigated by ring barking the roots or severing mature roots in both unpruned and pruned plants. Translocation of leaf assimilates to the root system appears to be dependent on a feeder root stimulus, and nitrogen assimilation by the root system seems to depend on replenishment of root reserves by leaf activity, both of which were interrupted by ring barking."

(1)http://coffeetea.about.com/od/preparation/a/growingtea.htm (2)http://aob.oxfordjournals.org/cgi/content/abstract/42/4/931

8.05

Don’t know.


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