Variation in leaf morphology of the invasive cat's claw creeper Dolichandra unguis-cati (Bignoniaceae)

Abstract

The invasive liana cat’s claw creeper Dolichandra unguis-cati (L.) L.G. Lohmann (syn. Macfadyena unguis-cati (L.) A.H. Gentry) exhibits intraspecific variation in leaf morphology, but this is rarely noted in the published literature. The present study documents variation in leaf morphology in two forms of the species that occur in Australia (long pod and short pod). Leaf morphology is compared between the two forms and the position of the shoots (trunk and ground) at the only two sites in which they co-occur. Leaves were categorised on the basis of leaflet number and the presence or absence of tendrils. Simple leaves were produced mainly on shoots growing along the ground and were more abundant in the short-pod form. Long-pod plants were dominated by bifoliate leaves with tendrils. Cat’s claw creeper exhibits considerably wider variation in leaf morphology than recorded previously. Variations in leaf morphology may be linked to differences in the genotype, developmental stage and plastic responses of the plants. Understanding these variations may have implications for taxonomic delimitation and improved management, particularly biological control involving leaf-feeding insects.

Comparison of growth traits between abundant and uncommon forms of a non-native vine, Dolichandra unguis-cati (Bignoniaceae) in Australia

“…Previous studies have found that the two forms showed differences in some life history traits. Boyne et al (2013) found a wide variety of leaf morphology for this species, but also reported that SP had significantly more simple leaves than LP.…”

“…In Australia, previous field surveys have revealed that there were seven sites in south-east Queensland (Qld) where LP has been reported, two at which it co-occurs with SP (Boyne et al 2013;Dhileepan 2012;Shortus and Dhileepan 2011). Recently, seven more sites were identified, bringing the total number of known sites to 14 in south-east Qld where LP occurs (Liz Snow (Biosecurity Queensland), pers.…”

Germination Biology and Occurrence of Polyembryony in Two Forms of Cats Claw Creeper Vine, <i>Dolichandra unguis-cati</i> (Bignoniaceae): Implications for Its Invasiveness and Management

“…The differences in germination dynamics and frequency of polyembryony between SP and LP plants lends further credence to suggestions that the two forms of D. unguis-cati could be two extremes of the same species or even different species [33]. Anecdotal evidence suggests that the predominant form of D. unguis-cati in the native range is similar in appearance to the form being referred to as LP plants in Australia (Dhileepan K. personal comm.).…”

“…SP is the more prevalent form in Australia and occurs in eastern Queensland and northeast New South Wales, while LP is only known from a few isolated localities in southeast Queensland (Dhileepan K, per. observation; [33]). SP is the form of D. unguis-cati that regarded as an environmental weed in different parts of the world [33] [34].…”

“…observation; [33]). SP is the form of D. unguis-cati that regarded as an environmental weed in different parts of the world [33] [34]. LP does not appear to be as invasive as SP as it occurs in only a few localities in southeast Queensland.…”