Document ID: chunk:federal_register_of_legislation:F2024L00346:reg:3:p1
Version: federal_register_of_legislation:F2024L00346
Segment Type: reg
Provision Reference: reg 3 (pt 1/10)
Character Range: 26609–29622

3               Species description and habitat

3.1                 Biology

Description
Spiny Rice-flower is a perennial, slow-growing sub-dioecious shrub (DSE 2008; Cropper 2004). It has dull green and hairless oval leaves 2–10 mm long and 1–3 mm wide (Carter & Walsh 2006). New growth is soft, smooth, and almost herbaceous which develops into short spiny (spinescent) divaricate branches and stems. The stem tips become hard, leafless and form a spinescent tip as the plant gets older (Walsh & Entwisle 1996). The flowers are produced in a terminal compact head (inflorescence). The inflorescences are clusters of 6–12 small, unisexual (rarely bisexual) flowers which are hairless and cream in colour. Inflorescences are subtended by four leaf-like bracts 3–7 mm long and 1.5–4 mm wide. The 2–3 mm long flowers are glabrous (hairless) and have four rounded, petal-like lobes (Carter & Walsh 2006). Female flowers are slightly smaller than male flowers and have two small non-functional anthers while the male flowers bear anthers with bright orange pollen. The fruit is ovoid or ellipsoid, 2–3 mm long, and has a thin, initially fleshy layer around a slightly woody 'stone' that encloses the single, oily seed (Walsh & Entwisle 1996; Carter & Walsh 2006).
The majority of individuals observed in the wild are sub-dioceous, although, hermaphroditic (bisexual) individuals are also present (Foreman 2012; Reynolds 2013). Across populations observed, the female phenotype appears to be more abundant than male or hermaphroditic individuals (Dear 2019). A male individual bears all male flowers or predominantly male flowers and conversely, a female individual bears all or predominantly female flowers and there is a clear phenotypic distinction between flowering male and female individuals (Figure 1). An individual is considered hermaphroditic when it produces a relatively balanced ratio of male and female flowers. In a hermaphroditic individual, each inflorescence is exclusive to either male or female flowers (Figure 2) (Carter & Walsh 2006; Foreman 2012; Reynolds 2013). A hermaphrodite individual could change its presentation of flowers over the season, but it will always have both flower types present (Reynolds 2013). Further investigation on how changes of sex expression may affect maintenance of long-term population viability is required to assist with species recovery planning, such as population monitoring and translocation strategy.

Life cycle
Flowering occurs over winter from April through to August (Figure 3), unlike the majority of other grassland plants in this ecosystem (Entwisle 1996; Walsh & Entwisle 1996). Germination in situ has been observed between May until November and appears to be stimulated 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