Gladiolus (Gladiolus natalensis)

Present distribution

Scientific name:	Gladiolus natalensis Hort.Lugd.Bat. ex Lodd.
Common name(s):	gladiolus

This weed is not known to be naturalised in Victoria

Habitat:

Grassy places & open woods to 2000 m, regions with summer rainfall (PFAF 2009). Montane grassland, moist woodlands or wooded grassland,
drought tolerant (Kipli 2009). Fernland (New Zealand) (Esler 1978). Woodlands, shallow wetlands (FLZAM 2009). Requires well drained soil, not
very cold hardy (PFAF 2009). Sandy and loamy soils, moist (PFAF 2009).

Potential distribution

Potential distribution produced from CLIMATE modelling refined by applying suitable landuse and vegetation type overlays with CMA boundaries

Map Overlays Used

Land Use:

Ecological Vegetation Divisions

Colours indicate possibility of Gladiolus natalensis infesting these areas.

In the non-coloured areas the plant is unlikely to establish as the climate, soil or landuse is not presently suitable.

Red= Very high	Orange = Medium
Yellow = High	Green = Likely

Impact

QUESTION	COMMENTS	RATING	CONFIDENCE
Social
1. Restrict human access?	“such a propensity to increase” (COBK 2009). “The flowers are scarlet, on a greenish-yellow ground, produced in long, one-sided spikes; the stems sometimes four feet high, with fifteen or twenty buds and blooms”(COBK 2009). Corm growing to 1.5 m. (PFAF 2009). May provide a semi permanent barrier over some distance to access a waterway. Low nuisance value. Impedes individual access; unable to walk to waterways.	ML	MH
2. Reduce tourism?	“It has such a propensity to increase, that it has become very common, and is now looked upon with indifference” (COBK 2009). Ornamental flower (FLZAM 2009). Therefore public perception may vary / some recreational uses may be affected.	M	M
3. Injurious to people?	It is used in parts of West and southern Africa in preparations to cure both constipation and severe dysentery, and is highly esteemed in curing snake-bite; the Corms maybe eaten; the starchy Corms are boiled and then leached in water before they are eaten (FLZAM 2009). If eaten uncooked may cause some physiological issues (Forsyth 1968). Spines, burrs or toxic properties at most times of the year.	MH	MH
4. Damage to cultural sites?	Likely to at least have a moderate visual effect due to its propensity to rapidly increase in abundance (COBK 2009). Moderate visual effect.	ML	MH
Abiotic
5. Impact flow?	Not reported to grow on stream/ river banks (pers obs)…. A number of reports of: Needs good drainage (DG 2009; GDI 2009; PFAF 2009). Unlikely to impact flow.	L	MH
6. Impact water quality?	Not reported to grow on stream/ river banks (pers obs)…. A number of reports of: Needs good drainage (DG 2009; GDI 2009; PFAF 2009). Although one report of it occasionally found in dambos (shallow wetlands) (FLZAM 2009). And contains toxins (DG 2009).	L	MH
7. Increase soil erosion?	Dies down to a corm over summer (KIPLI 2009). “such a propensity to increase” (COBK 2009). “The heavy spikes begin to topple after heavy rain or wind (GDI 2009). Not enough information on soil holding capacity of Gladiolus roots (pers obs).	M	M
8. Reduce biomass?	Dies down to a corm over summer (KIPLI 2009). “such a propensity to increase” (COBK 2009). Does not appear to be very competitive as to displace other vegetation, but in disturbed areas can quickly increase in abundance, in such a scenario biomass may increase or remain the same, but as it dies back over summer (Kipli 2009) it may reduce biomass. Not enough information.	M	L
9. Change fire regime?	No information, Dies back annually and resprouts in spring (Kipli 2009). May provide some fuel when growing in high density (AGHO 1996) and after they all die back.	M	ML
Community Habitat
10. Impact on composition (a) high value EVC	Climate modelling predicts that this species is not likely to establish as a weedy species in Victoria. No impact on EVCs in Victoria.	L	MH
(b) medium value EVC	Climate modelling predicts that this species is not likely to establish as a weedy species in Victoria. No impact on EVCs in Victoria.	L	MH
(c) low value EVC	Climate modelling predicts that this species is not likely to establish as a weedy species in Victoria. No impact on EVCs in Victoria.	L	MH
11. Impact on structure?	Usually increase in numbers each year (AGHO 1996). Does not appear to be particularly invasive but does well in open disturbed sites (Kipli 2009)\ so may prevent regeneration of native species in these areas.	M	MH
12. Effect on threatened flora?	“This species is not particularly invasive and I’ve not seen it away from disturbed edges of bushland (Kipli 2009). No examples of it having a direct affect on any threatened flora species (pers obs). As it can increase in numbers rapidly (AGHO 1996; COBK 2009). it does have the potential to reduce numbers of a threatened species – but no information for that. Any population of a VROT spp is reduced.	ML	M
Fauna
13. Effect on threatened fauna?	Usually increase in numbers each year (AGHO 1996). Known to be toxic when consumed (DG 2009; Forsyth 1968). May therefore reduce habitat/food abundance.	ML	M
14. Effect on non-threatened fauna?	Usually increase in numbers each year (AGHO 1996). Known to be toxic when consumed (DG 2009; Forsyth 1968). Likely to reduce food abundance to some degree. Minor effects on fauna species; minor hazard or reduction in habitat/ food/ shelter.	ML	MH
15. Benefits fauna?	Has a copious amount of nectar… therefore likely to provide food for nectar feeding birds and insects….and possibly other nectar feeding animals. Provides some assistance in either food or shelter to desirable species.	MH	MH
16. Injurious to fauna?	Usually increase in numbers each year (AGHO 1996). Known to be toxic when consumed (DG 2009; Forsyth 1968; COBK 2009). Large spines or burrs dangerous to fauna. Toxic, and/or causes allergies.	H	MH
Pest Animal
17. Food source to pests?	“High populations of thrips insects that have built up by then are devastating to the flowers, and spider mites attack the foliage” (LSUCEN 2009). Gladiolus thrips may be transported on the corms and consequently are usually present wherever gladiolus are grown; Scab, bacterial blight, botrytis rot, yellows, and dry rot all live part of their life cycle on the corms. (GDI 2009). Supplies food for one or more minor pest species. (eg. Blackbirds or environmental insect pests).	ML	MH
18. Provides harbour?	Not enough information, has no spines, thorns, burrs, can grow in high densities (AGHO 1996), therefore, may provide harbour to animals such as bush rabbits, rats, etc, although corms and plant parts contain toxins – so unlikely to provide food to these pests (DG 2009: AGHO 1996). Capacity to harbour rabbits or foxes at low density or as over night cover.	MH	M
Agriculture
19. Impact yield?	It occurs in grasslands and woodlands and occasionally in dambos (shallow wetlands) (FLZAM 2009). Therefore is likely to be a pasture weed, and could therefore reduce food availability in some areas – but no reports of it being a pasture weed (pers obs).	L	M
20. Impact quality?	“The author has seen a market gardener’s horse which recovered from acute colic and diarrhoea, the result of eating the corms of gladioli (Forsyth 1968). Toxic properties which could reduce the quality of some livestock. Minor impact on quality of produce (eg < 5% reduction).	ML	MH
21. Affect land value?	Unlikely to have a large effect on land value… not reports of this in the literature (pers. Obs).	ML	M
22. Change land use?	Affect on pasture grasses for grazing may be significant but not enough information to determine whether the likelihood of the plant causing a change in land use (pers. Obs).	M	M
23. Increase harvest costs?	Not enough information.	M	L
24. Disease host/vector?	“High populations of thrips insects that have built up by then are devastating to the flowers, and spider mites attack the foliage” (LSUCEN 2009). Gladiolus thrips may be transported on the corms and consequently are usually present wherever gladiolus are grown; Scab, bacterial blight, botrytis rot, yellows, and dry rot all live part of their life cycle on the corms. (GDI 2009). Provides host to minor (or common) pests, or diseases.	M	MH

Invasive

QUESTION	COMMENTS	RATING	CONFIDENCE
Establishment
1. Germination requirements?	It usually germinates freely (PFAF 2009). Planting corms after march will result in disappointment (LSUCEN 2009) and seeds require heat and moisture and germinate in spring (SHEGRE 2009). Requires natural seasonal disturbances such as seasonal rainfall, spring/summer temperatures for germination.	MH	MH
2. Establishment requirements?	Grassy places and open woods at elevations to 2,000 metres in Natal; Regions with summer rainfall (PFAF 2009). In montane grassland, moist woodlands or wooded grassland (Kipli 2009). Grassland fernland (NZ) (Esler 1978). It occurs in grasslands and woodlands and occasionally in dambos, (shallow wetlands) (FLZAM 2009).	ML	MH
3. How much disturbance is required?	“I’ve not seen it away from the disturbed edges of bushland” (Kipli 2009). More open habitats: In montane grassland, moist woodlands or wooded grassland (Kipli 2009). Establishes in relatively intact or only minor disturbed natural ecosystems	MH	MH
Growth/Competitive
4. Life form?	Corm, perennial (AGHO 1996). Herbaceous monocotyledon (NZPCN 2009). Geophyte, climber or creeper.	ML	MH
5. Allelopathic properties?	Not mentioned in literature.	M	L
6. Tolerates herb pressure?	Reports of plant parts being poisonous if ingested (DG 2009; Forsyth 1968) and corms having to be boiled before consumption (FLZAM 2009). Resprouts from corm in spring (Kipli 2009). Likely to tolerate herbivory. Consumed but non-preferred or consumed but recovers quickly; capable of flowering /seed production under moderate herbivory pressure (where moderate = normal; not overstocking or heavy grazing).	MH	MH
7. Normal growth rate?	Annual. No specific information on growth rate. Moderately rapid growth that will equal competitive species of the same life form.	MH	MH
8. Stress tolerance to frost, drought, w/logg, sal. etc?	Cultivated on farms in the forest (FLZAM 2009), some shade tolerance. G. dalenii (syn: Gladiolus natalensis) is a herbaceous perrenial plant that dies down to a corm over summer, therefore survives drought (Kipli 2009). The plant prefers light (sandy) and medium (loamy) soils and requires well drained soil. The plant prefers acid, neutral and basic (alkaline) soils. It cannot grow in the shade. It requires moist soil (PFAF 2009). This species is not very cold-hardy, tolerating temperatures down to about 0°C (PFAF 2009). Tolerant to at least two and susceptible to at least one.	ML	MH
Reproduction
9. Reproductive system	Gladiolus is propagated by seed as well as vegetative means i.e. by corms and cormels (PLNI 2009). Both vegetative and sexual reproduction (vegetative reproduction may be via cultivation, but not propagation).	H	MH
10. Number of propagules produced?	No information.	M	L
11. Propagule longevity?	No information.	M	L
12. Reproductive period?	Will return for years without digging and storing (LSUCEN 2009). Forms self sustaining monoculture.	H	MH
13. Time to reproductive maturity?	1-2 years (PFAF 2009). Produces propagules 1-2 years after germination.	MH	MH
Dispersal
14. Number of mechanisms?	It is a striking ornamental plant, now widely cultivated (FLZAM 2009). Seeds (no mention in literature of how they are dispersed) and corms. Deliberate human dispersal (propagation or planting).	ML	MH
15. How far do they disperse?	Natural seed dispersal: no information, spread by humans as ornamental. Greater than 1 km by humans but naturally – not enough information.	M	L

References

AGHO (1996) Texas Agricultural Extension service, A&M University - Horticultural update March 1996. Available at http://aggiehorticulture.tamu.edu/home/update/HUMAR96.pdf (verified 03/2009).

COBK (2009) Chest of books – The Flower garden. Available at http://chestofbooks.com/flora-plants/flowers/The-Flower-Garden/Gladiolus-Corn-Flag.html (verified
03/2009).

Esler, A. E. (1978) Botanical Features of Tiritiri Island, Hauraki Gulf, New Zealand. New Zealand Journal of Botany, 1978, Vol. 16: 207-26.

FLZAM (2009) Flora Zambesiaca. Available at http://apps.kew.org/efloras/namedetail.do?flora=fz&taxon=9957&nameid=26422 (verified 03/2009).

GDI (2009) Gardening Ideas. Available at http://www.gardeningideas2you.com/homeandgardening/gladiolus.html (verified 03/2009)

Kipli (2009) Posted in Iridaceae, Sydney Royal Botanic Garden, blog. Available at http://kipili.com/?cat=18 (verified 03/2009).

LSUCEN (2009) lsuagcenter.com Research and Extension LSU AG centre. Available at http://www.lsuagcenter.com/en/lawn_garden/home_gardening/flowers/Glad+Tidings+Sword+Lillies+Beautiful+Easy+To+Grow.htm (verified 03/2009).

NZPCN (2009) New Zealand Plant Conservation Network. Available at http://www.nzpcn.org.nz/exotic_plant_life_and_weeds/detail.asp?WeedID=1623 (verified 03/2009).

PFAF (2009) Plants for a future database. Available at http://www.ibiblio.org/pfaf/cgi-bin/arr_html?Gladiolus+dalenii (verified 03/2009).

PLNI (2009) Planning.up.nic.in - Area Development Scheme for Gladiolus Cultivation (Sanguem, Quepem, Sattari and Ponda blocks) Available at
http://planning.up.nic.in/innovations/inno3/ph/gladiolus.htm (verified 03/2009).

Sabonet (2009) Plants of the Nyika Plateau (variation in synonyms/ names) Available at http://www.bbg.org/gar2/topics/plants/2006sp_glads.html. (verified 03/2009).

Global present distribution data references

Australian National Herbarium (ANH) (2008) Australia’s Virtual Herbarium, Australian National Herbarium, Centre for Plant Diversity and Research, Available at
http://www.anbg.gov.au/avh/ (verified 17/02/2009).

Department of the Environment and Heritage (Commonwealth of Australia). (1993 – On-going) Australian Plant Name Index (APNI)
http://www.cpbr.gov.au/apni/index.html (verified 07/05/2009).

Global Biodiversity Information Facility (GBIF) (2008) Global biodiversity information facility, Available at http://www.gbif.org/ (verified 17/02/2009).

Integrated Taxonomic Information System. (2009) Available at http://www.itis.gov/ (verified 07/05/2009).

Missouri Botanical Gardens (MBG) (2009) w³TROPICOS, Missouri Botanical Gardens Database, Available at http://mobot.mobot.org/W3T/Search/vast.html (viewed 17/02/2009).

United States Department of Agriculture. Agricultural Research Service, National Genetic Resources Program. Germplasm Resources Information Network
- (GRIN) [Online Database]. Taxonomy Query. (2009) Available at http://www.ars-grin.gov/cgi-bin/npgs/html/taxgenform.pl (verified 26/03/2009).

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