Document ID: chunk:federal_register_of_legislation:F2024L00346:reg:3:p2
Version: federal_register_of_legislation:F2024L00346
Segment Type: reg
Provision Reference: reg 3 (pt 2/10)
Character Range: 29347–32335

by cool winter and spring temperatures (Foreman 2011; Reynolds 2013), suggesting physiological dormancy. When seeds germinate, the seedlings stay as non-reproductive recruits for one year and will enter the juvenile stage after the second year. Some juvenile plants may start to reproduce but at much lower rates than adult plants. Individuals may remain as juveniles until approximately five years of age before moving on to the adult stage, where reproduction and survival is higher (Figure 3; Regan et al. 2021). Individuals remain reproductively active until they senesce (Mueck 2000; Carter & Walsh 2006). Spiny Rice-flower is a long-lived species with a lifespan estimated up to 100 years (Mueck 2000 cited in Carter & Walsh 2006; Regan et al. 2021). The generation time is estimated to vary between 50 to 80 years (Mueck 2000; Foreman 2005; DELWP 2021).
Figure 1 A contrasting phenotype of male (left) and female plant (right), both in flowering stage. Male plants bear more showy flowers than female (see Figure 2 for flower close-up).
Photo © Debbie Reynolds

Figure 2  Flowers of Spiny Rice-flower. Left–female inflorescence, Middle–male inflorescence, Right–hermaphroditic individual bearing seeds and male flowers.

Photo © Debbie Reynolds
Figure 3 Conceptual model of the timing of ecological processes including the effect of fire across seasons.
Source: Regan et al. (2021)

Reproduction

Pollination
As the Spiny Rice-flower is predominantly an outcrossing species (DEWHA 2009a; James 2012) there is a need to transport pollen between male and female plants, making it particularly vulnerable to a lack of pollinators (Reynolds 2013). Insect pollinators such as introduced honeybees, lycaenid butterflies (Foreman 2005), beetles (Cropper 2004), Dipteran and Hymenopteran flies (Cropper 2009) have been reported to visit Spiny Rice-flower (Foreman 2012) (Figure 4). These insect pollinators have small home ranges and are only able carry pollen over short distances, and thus effective pollination and seed production are affected by the spatial distribution of the individuals and populations, as well as the size and density of the population (Reynolds 2013). Genetic analysis suggests that most seeds result from outcrossing by insect pollinators (James & Jordan 2014) but viable seeds are known to be produced through selfing (pollen from male flowers on the plant fertilising female flowers on the same plant) in hermaphroditic plants through geitonogamy, indicating that there is a degree of self-compatibility in the breeding system (TSSC 2016).

Seed and germination traits
Seed fecundity and viability levels are relatively high and stable (Reynolds 2013). Seed production or fecundity, expressed as number of seeds per stem, is generally dependent on temperature and rainfall. Rainfall was relatively high in 2010, effectively ending a 13-year period of drought, and this was reflected in a lower seed fecundity across Spiny Rice-flower female individuals on the