Identification of the Three Species of Featherbushes
Aulax pallasia NEEDLE-LEAF FEATHERBUSH has needle-like leaves, the male flowerheads are branched, the female flowerhead bears small sterile male flowers, the cone consists of untidy fine branches, and, most useful of all: the plant is multi-stemmed and resprouts after a fire from an underground lignotuber. The other two species are single-stemmed and killed by fire: Aulax umbellata BROAD-LEAF FEATHERBUSH has flat leaves and Aulax cancellata has needle-like leaves with a channel on the upper surface and fruit with a meshed coat.
It turns out that Aulax umbellata has a form, which occurs between Sir Lowrys Pass and Kleinmond, with very narrow leaves, which could easily be confused with Aulax cancellata (Rourke 1987). A groove on the leaf would clearly distinguish Aulax cancellata - but, confound it, the groove may be relatively inconspicuous in populations of Aulax cancellata in the area. In fact, the photograph on page 211 of Marie Vogts book shows a female Aulax cancellata with relatively broad leaves. It also cleary shows another useful feature in distinguishing the two species (in addition to the fruit) - the reduced cone branches surrounding the flowers: these are finely branched only at the tip in Aulax cancellata. By contrast, in Aulax umbellata (see Vogts 1982: page 212) these branch much lower down, giving a relatively stout and untidey appearance to the cone branches.
Fortunately, identifying the two species in other areas is relatively easy, since elsewhere Aulax umbellata has very wide leaves and Aulax cancellata has needle-like leaves with an upper groove. In fact, the task is made easier by the two species not overlapping in their distribution ranges anywhere but between Sir Lowrys Pass and Kleinmond - makes you wonder, doesnt it? And, if youre into wondering, why does only Aulax cancellata occur on the Cape Peninsula?
Briefly the species can be identified as follows:
Resprouter, leaves needle-like 1-5 mm wide, rounded to flattened
Killed by fire, leaves 2-15 mm wide, flat, cupule branchlets with ancillary sterile florets
Killed by fire, leaves 0.5 -3mm wide, channelled when dried, cupuled branchlets columnar without side branches