Literature review: Impact of Chilean needle grass ... - Weeds Australia

(Barkworth 2006), 10-25 cm (Barkworth and Torres 2001), 5-30 cm (Burkart 1969), 10-25 cm (Moraldo 1986), 13-28 cm (Baeza
et al. 2007), 14-35 cm (Zanin 2008) or 20-35 cm long (Martín Osorio et al. 2000) or up to 30 cm long, open, branches drooping,
flexuous (Jacobs et al. 1989, Edgar and Connor 2000) or erect to nodding (Barkworth 2006), up to 40 cm long, “the branches
breaking up at maturity” (Carolin and Tindale 1994 p. 772); loose (Walsh 1994, Muyt 2001), lax, nodding (Hayward and Druce
1919), drooping (Muyt 2001), sometimes interrupted, to 40 cm long (Walsh 1994); rachis smooth to slightly scabrous, branches and
pedicels with stiff hairs (Jacobs et al. 1989); pedicels 1.5-12 mm (Baeza et al. 2007); branches thin, angular, scabrid (Hayward and
Druce 1919) or pubsecent (Martín Osorio et al. 2000); overall “very distinctive purplish colour” (Duncan 1993) or “initially ...
striking violet ... with ....green awns” (Slay 2002c); branches 2.5-8.5 cm with 2-5 spikelets (Barkworth 2006), 3-5 spikelets (Hayward
and Druce 1919), average of c. 15 spikelets in the aerial section and a progressive reduction in length of infloresence sections and
number of spikelets at lower nodes (Connor et al. 1993), averages of 16 to 27.4 seeds per panicle (Gardener et al. 2003a).
Disarticulating above the glumes (Verloove 2005). Published descriptions often lack precise descriptions of the subsidiary
clandestine panicle sections. According to one description (Jacobs et al. 1989, Edgar and Connor 2000): “Occasionally an aerialtype
branch may be produced at the uppermost culm node, and so far as can be judged, remains unsheathed”. This may be
equivalent to what Slay (2002c p. 21) refers to as “another ‘emerged seed head’ [that] may develop from the top node underneath
the terminal leaf sheath” on larger plants (see his Fig. 26). Slay (2002a) noted that such secondary panicles develop in the leaf
sheath of all culm nodes, are progressively smaller towards the base of the plant and may occasionally produce exposed,
strongly-awned seed. The ‘overt’ panicle is purplish in the flowering stage, becoming more silver as the seeds ripen (Bourdôt
and Ryde 1986). Plants grown from single tillers and from seed produced a mean of 18 and 16 panicles per plant respectively
after 6-9 months (Hartley 1994). The potential seed yield per panicle of plants in a dense sward in New Zealand was 38 (Slay
2001). As in other paniculate grasses, the panicle matures basipetally, the uppermost spikelet developing first (Stebbins 1972).
Flowers:
hermaphrodite; pedicels 1-8 mm long, angled, scabrous, pubescent (Barkworth 2006), drooping (Slay 2002c); terminal panicle
spikelets – glumes unequal (Hayward and Druce 1919) or subequal (Walsh 1994, Barkworth 2006); 10-22 mm (Barkworth 2006),
16-20 mm (Walsh 1994), 15-25 (Moraldo 1986), 16-25 (Walsh 1998), 14-21 mm (Barkworth and Torres 2001), up to c. 2 cm (Weber
2003), 15-20 mm long (Verloove 2005), shorter than the awn column, the upper to 15 mm, the lower to 20 mm (Jacobs et al. 1989)
or the lower 17-20 mm long and the upper 2-3 mm shorter (Martín Osorio et al. 2000) or the lower 13-15 mm and the upper 12-
14 mm (Baeza et al. 2007); the lower 15-17 x 0.4-1 mm, the upper 13-15 x 0.5-1 mm (Zanin 2008); 1.8-2.3 mm wide (Barkworth
2006), narrowly lanceolate (Martín Osorio et al. 2000, Barkworth 2006), linear lanceolate (Hayward and Druce 1919), acuminate
(Hayward and Druce 1919, Walsh 1994), produced into awn-like processes to 3 mm (Jacobs et al. 1989); 3-5 veined (Barkworth
2006), 3-nerved (Hayward and Druce 1919, Jacobs et al. 1989, Zanin 2008), the lower 3-nerved (Martín Osorio et al. 2000), or 5-
nerved, the upper 3-nerved, scabrous-pubescent on the nerves and/or margins (Verloove 2005), nerves scabrous (Moraldo 1986,
Jacobs et al. 1989), central nerve prominent with rigid hairs, lateral nerves with rudimenary hairs and lightly rough (Martín
Osorio et al. 2000); glabrous (Jacobs et al. 1989, Watson and Dallwitz 2005, Barkworth 2006); overall maroon (Cook 1999) or
purple (Bourdôt and Ryde 1986), the lower violet, the upper clear to violet at anthesis (Slay 2002c); violet below, hyaline above
(Jacobs et al. 1989), strongly (Walsh 1994) purplish with hyaline apex and margins (Verloove 2005), hyaline or violet (Moraldo
1986), hyaline and dyed purple in the upper half (Martín Osorio et al. 2000), green-violet (Baeza et al. 2007), brownish with white
margins (Hayward and Druce 1919), losing colour but retained on plant for some time after seed fall (Muyt 2001), retaining a
pinkish tinge even after the seeds have dropped (Liebert 1996); florets 6-13 mm long, 1-1.5 mm wide, terete, widest just below
the crown (Barkworth 2006); anthoecium (including callus, lemma body and crown, plus the concealed palea) cylindrical, 7.5-9
mm but up to 10 mm long, diameter c. 1.2 mm (Verloove 2005) or ±cylindrical 7-11.5 mm long (Barkworth and Torres 2001) or
fusiform 6.3-11.5 mm long, c. 1-1.5 mm wide, white or violet in colour (Burkart 1969), purple (Muyt 2001) or corona purple
(Bourdôt and Ryde 1986), lemma white, corona violet, awn light green at anthesis (Slay 2002c); basal spikelets more or less
cleistogamous, enclosed by uppermost leaf sheath (Burbidge and Gray 1970), other spikelets chasmogamous. [“In the Australian
species [of Stipa sens. lat.] there are no externally visible differences between the two, but the cleistogamous spikelets usually
have shorter stamens. Both types may be found scattered through a panicle” (Vickery at al. 1986 p. 11)]; lemma and palea – see
description below under ‘Fruit’; ovary glabrous (Jacobs et al. 1989); lodicules (scales below the stamens and ovary, regarded as
a reduced perianth): 2, c. 1mm (Jacobs et al. 1989), membranous, glabrous (Watson and Dallwitz 2005), hyaline, transparent
(Baeza et al. 2007), nerveless; styles 2, plumose (Jacobs et al. 1989); ovary 1-1.5 mm, glabrous (Baeza et al. 2007); stigmas 2
(Watson and Dallwitz 2005), white (Slay 2002c), 2-2.5 mm (Baeza et al. 2007); anthers 3, penicillate,3-3.5 (Barkworth 2006) or
4-4.5 mm long (Baeza et al. 2007), or up to 3.2 mm long in chasmogamous flowers and in cleistogamous flowers reduced to one
fertile 0.5-0.7 mm long and 2 sterile, 0.1-0.2 mm long (Edgar and Connor 2000), yellow (Slay 2002c); pollen grains smaller than
in Aveneae, almost spherical (tribal characters, Tsvelev 1977).
axillary cleistogamous spikelets - extremely variable (Gardener and Sindel 1998); the various floral parts are progressively
reduced in number and size from the upper to the basal spikelets (Connor et al. 1993) i.e. loss of glumes and reduction of awn.
See description under “Cleistogenes”, below.
Fruit = ‘seed’ (Fig. 2). Caryopsis “a dry monospermic indehiscent fruit” (Sendulsky et al. 1986);( = grain, includes the hilum and
embryo). 3.5-5 x 0.6-1 mm (Zanin 1998), 4.8-5.5 x 0.9-1.2 mm (Baeza et al. 2007), 3-5 (Barkworth 2006), 4-5 mm (Verloove
2005) or 6-8 mm (Martín Osorio et al. 2000) long; cylindrical (Burkart 1969), obovoid (Baeza et al. 2007); tightly enclosed by
the lemma (Bourdôt and Ryde 1986); clear-coffee coloured (Baeza et al. 2007); hilum (the scar left on the caryopsis at the point
of attachment) linear (Jacobs et al. 1989), 2 mm long (Baeza et al. 2007); embryo small (Jacobs et al. 1989), 1.5-1.6 mm (Baeza et
al. 2007), festucoid, 1 / 6 - 1 / 3 of the grain (for Stipeae- Tsvelev 1984), with an epiblast and a neglibible mesocotyl internode,
without a scuteller tail (Watson and Dallwitz 2005); endosperm hard, without lipid, containing compound starch grains (Watson
and Dallwitz 2005).
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