Skip to main content

Subscribe to Newsletter

Name

Cleistochloa subjuncea

C.E.Hubb.

(Cly-sto-klo-a; sub-jun-see-a)

A wiry perennial grass, up to 60 cm tall (Fig. 1). The leaves arise from along the stem (cauline) and are quite variable in size (Fig. 2). Two types of spikelets (the basic flowering unit) are found, one type consists of open spikelets which are carried in groups of 2-6 on a terminal spike (Fig. 3) and the second consists of closed spikelets which are carried as solitary spikelets in the branch and leaf axils, usually partially enclosed by the leaf sheath (that part of the leaf that clasps the stem) (Fig. 4). When the grass dries off, the leaf sheath loosens from the stem/culm and the leaf blade breaks off (Fig. 5).

BOTANICAL DESCRIPTION
A wiry perennial to 0.6 m tall, bases covered with thick scales (cataphylls) although these are not always obvious (Fig. 6). Leaf blades 1-6 cm long, to 3 mm wide, hairy or glabrous (Fig. 2). Terminal inflorescence an erect raceme, 0.7-3.5 cm long, consisting of 2-6 chasmogamous spikelets borne alternately along the axis (Fig. 3). Chasmogamous spikelets 3.5-5 mm long, almost glabrous. Lower glume < 1 mm long; upper 5-nerved, 3-4 mm long. Lower lemma 3.5-4.5 mm long, hairy on the upper margins and apex but glabrous on the surface; upper lemma as long as the spikelet. Cleistogamous spikelets partly enclosed by the leaf sheaths, 4-6 mm long, obtuse, usually apiculate (Fig. 4).

DIAGNOSTIC FEATURES
This genus is recognised by the tufted wiry stature of the plant, the indistinct flowering heads, and the spikelets partially enclosed in the leaf axils. Cleistochloa sclerachne also occurs in the Cape York Peninsula Region (CYP) and can be distinguished from C. subjuncea by the wider and longer leaf blades, and the hairy surface of the lower lemma of the terminal spikelets (Fig. 7). Sterile specimens of Paspalidium gracile have a similar wiry form and are difficult to distinguish without spikelets, they lack the spikelets in the leaf axils and have a bristle which extends beyond the terminal spikelets (Fig. 8 & 9).

HABITAT
In tropical and subtropical rain forests, Brigalow forests, tropical and subtropical sub-humid woodlands, and semi-arid shrub woodlands, often associated with sandstone and poorer soils (Simon & Alfonso 2011) (Fig. 10). Collections are located in the lower eastern quadrant of the Cape York Peninsula (Fig. 11), and the Mitchell River Catchment may be on the edge of this species’ distribution.

LAND MANAGEMENT NOTES

Flowers sporadically throughout the year.

Fig. 1. Image of Cleistochloa subjuncea plant (PHOTO: RJ Cummings d18686a).
Fig. 1. Image of Cleistochloa subjuncea plant (PHOTO: RJ Cummings d18686a).
Fig. 2. Image showing leaf variability within one tuft of Cleistochloa subjuncea (PHOTO: RJ Cummings d67829a).
Fig. 2. Image showing leaf variability within one tuft of Cleistochloa subjuncea (PHOTO: RJ Cummings d67829a).
Fig. 3. Image showing open (chasmogamous) spikelets on terminal raceme of Cleistochloa subjuncea (PHOTO: RJ Cummings d8687a).
Fig. 3. Image showing open (chasmogamous) spikelets on terminal raceme of Cleistochloa subjuncea (PHOTO: RJ Cummings d8687a).


 

Fig. 4. Image showing closed spikelet in axil of leaves of Cleistochloa subjuncea (PHOTO: RJ Cumming d18688a).
Fig. 4. Image showing closed spikelet in axil of leaves of Cleistochloa subjuncea (PHOTO: RJ Cumming d18688a).
Fig. 5. Cleistochloa subjuncea specimen showing leaf sheath wtih broken leaf blade (PHOTO: ATH, specimen QRS76630).
Fig. 5. Cleistochloa subjuncea specimen showing leaf sheath wtih broken leaf blade (PHOTO: ATH, specimen QRS76630).
Fig. 6. Cataphylls Cleistochloa subjuncea (PHOTO: ATH, specimen QRS76630).
Fig. 6. Cataphylls Cleistochloa subjuncea (PHOTO: ATH, specimen QRS76630).
Fig. 7. Image showing open spikelets on terminal raceme of Cleistochloa sclerachne (PHOTO: ATH, specimen ).
Fig. 7. Image showing open spikelets on terminal raceme of Cleistochloa sclerachne (PHOTO: ATH, specimen ).
Fig. 8. Image Paspalidium gracile (PHOTO: RJ Cummings d18656a).
Fig. 8. Image Paspalidium gracile (PHOTO: RJ Cummings d18656a).
Fig. 9. Image of inflorescence Paspalidium gracile (PHOTO: Harry Rose).
Fig. 9. Image of inflorescence Paspalidium gracile (PHOTO: Harry Rose).
Fig. 10. Lancewood (Acacia shirelyii) community with Cleistochloa subjuncea in ground layer (PHOTO: RJ Cummings d42676a).
Fig. 10. Lancewood (Acacia shirelyii) community with Cleistochloa subjuncea in ground layer (PHOTO: RJ Cummings d42676a).
Fig 11. Map of CYP bioregion showing actual herbarium collections
Fig 11. Map of CYP bioregion showing actual herbarium collections (from BRI and CNS) (solid circle) and site records (open circle) of Cleistochloa subjuncea. The green shading indicates areas where this species might also be found, based on the similarity of habitat to locations where the species has been recorded. (Mapping supplied by P. Bannink, DES). Data attribution: Environment and Science, Queensland Government, Biodiversity status of pre-clearing and 2015 remnant regional ecosystems series - version 10.0 licensed under Creative Commons Attribution.

 

Resources

AVH (2019). Australia’s Virtual Herbarium, Council of Heads of Australasian Herbaria, <http://avh.chah.org. au>, accessed 1 Mar 2019.

Hooker, Nanette B. (2016). Grasses of Townsville. James Cook University, Townsville, QLD, Australia.

PlantNET (The NSW Plant Information Network System). Royal Botanic Gardens and Domain Trust, Sydney. http://plantnet.rbgsyd.nsw.gov.au [May 2019].

Simon, B.K. & Alfonso, Y. (2011). AusGrass2, http:// ausgrass2.myspecies.info/accessed on [May 2019].