Distribution, Impact and Biology of the Other “Watsonias”, Chasmanthe
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78 Plant Protection Quarterly Vol.8(3) 1993 Having a name for biological species is desirable if we want to seek, store Distribution, impact and biology of the other andutilize biological data on things like reproduction, seed germination, seed lon- “watsonias”, Chasmanthe (African Corn Flag) and gevity, fire response etc. and ecological Crocosmia (Montbretia) in Western Australia information on the species. John Scott will undoubtedly mention the need to know the names of species we are dealing with Greg Keighery, Department of Conservation and Land Management, in the case of seeking biological control PO Box 51, Wanneroo, WA 6065, Australia. agents. However, in the genus Watsonia we have some problems naming the spe- cies present in WA. Summary Chasmanthe is widespread throughout ex Morren) N.E. Br. has become natural- How many species do we have the lower south west of Western Aus- ized in Australia (Cooke 1984). Both spe- recorded in this State? tralia. Chasmanthe has been recorded cies were widely grown as ornamentals A taxonomic account of all species of from 13 conservation reserves, and three (Montbretia is still available in the nurs- Watsonia in Australia was published in forest blocks, chiefly from highly dis- ery trade) and were originally introduced ‘Flora of Australia’ in 1986, but this only turbed sites. It can, however, invade as such. These two species have a very recognized six species (Table 1). The bushland if the initial introduction is similar habit to watsonia in leaf, and are Western Australian species were studied not removed. Sites most affected appear chiefly distinguished by weed control by Gillian Perry at the WA Herbarium, in to be on well drained calcareous soils in personnel and the public as “another spe- preparing the ‘Flora of the Perth Region’ contrast to the other “watsonias”. cies of watsonia” even when in flower. which was published in 1987, two years Crocosmia is sparingly naturalized on Only in Western Australia are both va- before publication of Goldblatt’s detailed vacant lots in towns and road verges rieties of Chasmanthe floribunda natural- study of all species (Table 1). We believed only in the higher rainfall areas of south ized: the typical var. floribunda with or- that there were eight species recorded for Western Australia. ange flowers and var. duckittii G. Lewis WA; these are treated differently in ex L. Bol. with yellow flowers, yellow- Goldblatt so, how do we deal with this Introduction brown anthers and a shorter floral tube. taxonomic confusion? Chasmanthe and Crocosmia are southern Why is there so much discrepancy in the African Iridaceae genera of three (De Vos Methods application of names? The reason must be 1985) and nine species (De Vos 1984) re- Distribution data was obtained from road that in WA we have variants which arose spectively. One species of each genus, logs, field note books and reserve lists through cultivation and we have hybrids, Chasmanthe floribunda (Salisb.) N.E.Br. compiled by the author from 1985 to the some of which were probably selected in and Crocosmia × crocosmiifolia (Lemoine present. All available published and the gardens at Rondebosch 163 years ago and some of which probably arose here in WA. At this stage of our knowledge we need not be concerned that we have difficulty in identifying the species we have; we can use interim names. We may use for exam- ple, a temporary or interim name like Watsonia species A or Watsonia “Busselton pink”. This poses no problem when we have computer databases which can cope with temporary names and easily enter other names as they are determined. The Department of Conservation and Land Management’s Herbarium has a sophisti- cated database which already has the watsonia collections entered. However, we need more specimens with full anno- tations on their locality, habitat and other observations which will enable us to build up a useful database of the biology of these insidious plants. Figure 1. Distribution of Chasmanthe floribunda in Western Australia. Plant Protection Quarterly Vol.8(3) 1993 79 Table 1. Chasmanthe occurrence in conservation areas. seed dispersal, especially after fires. Chasmanthe is abundant in areas of the Area Vegetation Source Mount Eliza escarpment of Kings Park, Wambyn NR Marri woodland 1 but is also widespread, though scattered, John Forest NP Streamline 1 in the remainder of the bushland (I.R. Serpentine NP Streamline 1 Dixon personal communication). Yanchep NP Tuart woodland 1 Chasmanthe has also been recorded in the Star Swamp Heath Bell et al. (1979) Perth area invading limestone heath at Mt Kings Park Limestone heath 1 Brown (System Six area M 92), under Mount Brown (M 92) Limestone heath 1 Tuart woodland at Woodman’s Point, Maylands foreshore (M 50) Drain Meney (1987) along the Swan River at Peppermint Point Resolution (M 59) Limestone quarry 1 Grove (System Six area M 54) and Point Freshwater Bay (M 54) Disturbed tuart woodland 1 Resolution (System Six area M 59) and in Ruabon NR Old clearing 1 Tuart woodland at Star Swamp Bushland Leeuwin-Naturaliste NP Disturbed karri (Boranup) 1 Reserve. Ellen Brook Streamside 1 Crocosmia (Figure 2) is only found in the Bold Park Roadside 1 high rainfall region of south western Western Australia, between Albany NR Nature Reserve (35.02 S, 117.53 E) and Margaret River NP National Park (33.57 S, 115.04 E). In this region the spe- 1 This paper cies has been recorded along roadsides, Table 2. Chasmanthe occurrence in State Forest areas. very disturbed creeklines and grassy river banks, and on vacant lots. Nearly all of Area or Forest Block CALM District Site these occurrences can be related to dump- ing of garden refuse or old habitation Dryandra Forest Narrogin Disturbed sites. It has only been recorded in a single Happy Valley Block Kirup Track conservation reserve, West Cape Howe Myalup Block Harvey Settlement National Park, where it is growing in an old unrehabilitated gravel pit. The largest manuscript bushland lists and collections Swan Coastal Plain from four localities: populations are around Wilson’s Inlet, at in the Western Australian Herbarium near Naval Base, 18 km south of Freman- Denmark. were also consulted. tle (System Six area M 92); Mount Eliza; Buckland Hill; and Waterloo, 13 km north Biology Results and discussion of Bunbury. Crocosmia (Montbretia) is a garden hybrid Most populations consist of 50–100 between Crocosmia aurea (Pappe ex Hook) Distribution plants, occupying less than 200 square Planchon and Crocosmia pottsii (Baker) Chasmanthe is widespread throughout the metres in area. They are largely found on N.E.Br., created in France in 1880. Plants wetter areas of the lower south west of vacant lots, old refuse sites and road and flower prolifically between December Western Australia, with over 120 locali- rail reserves. and February, but almost no viable seed ties recorded, although over half of these Chasmanthe has been recorded from 13 is set. Plants spread slowly via offshoots. are in the Perth metropolitan area. actual or proposed conservation reserves Chasmanthe flowers from July to Sep- Populations were found from Gin Gin in (Table 1) and three State Forest blocks tember, the bright red to yellow flowers the north, Narrogin inland and Albany in (Table 2) in south western Australia. attract nectar feeding birds, and copious the east (Figure 1). Disjunct occurrences These infestations are chiefly around amounts of viable seed are set. Daughter were recorded at Northampton (28.21 S, old townsites or rubbish dumps, or cormlets are produced at the end of the 114.38 E) and Bremer Bay (34.24 S, spreading along tracks, indicating that growing season. 119.23 E). human activity is the primary agent of Chasmanthe floribunda var. duckittii has spread. Invasion into intact remnant veg- Weediness only been recorded as naturalized on the etation can occur, via soil disturbance and Approximately 42 taxa of the family Iridaceae are naturalized in Western Aus- tralia (Table 3). Several are very signifi- cant weeds of both agricultural and con- servation lands. Table 3 lists the natural- ized Iridaceae of Western Australia rated as major, local, minor and non-bushland weeds based on their actual and potential impact on conservation areas. This rating can be best demonstrated by considering examples of some of the most serious weeds given below: Augusta Freesia × leichtlinii No. populations – greater than 100 Spread – Perth to Israelite Bay Presence in bushland – numerous populations Effects – smothers bulbous and annual herbs Denmark Seeding – prolific Figure 2. Distribution of Crocosmia × crocosmiifolia in Western Australia. Vegetative spread – produces 1 to 5 80 Plant Protection Quarterly Vol.8(3) 1993 Table 3. The major and minor environmental weeds in the family Iridaceae in Western Australia. Major Weeds Local weeds Minor weeds (species that have Non Bushland weeds (species rarely been recorded in that have not been recorded in bushland) bushland) Ferraria crispa Babiana disticha Babiana tuberosa Babiana stricta Freesia × leichtlinii Chasmanthe floribunda Gladiolus angustus Crocosmia × crocosmiifolia Gladiolus caryophyllaceus Hexaglottis lewisae Gynandiris setifolia Gladiolus alatus Gladiolus undulatus Hesperantha falcata Homoglossum watsonianum Gladiolus carneus (cardinalis) Homeria flaccida Romulea rosea var. communis Homeria collina Gladiolus communis Sparaxis bulbifera Watsonia marginata Moraea vegeta Gladiolus tristis Romulea rosea var. australis Watsonia versfeldii Ixia maculata Homeria ochroleuca Watsonia borbonica