Grasses of Cape Yorkork - Quinkan Country
Lepturus xerophilus Domin
This is an annual or possibly short-lived perennial. A semi-prostrate or spreading grass, rooting at the nodes with the flowering stems curving upwards at the tips, 30-90 cm high (Fig. 1). The leaves are cauline (arising along the stem of the plant) with flat or convolute (with margins rolled inwards with one overlapping the other) leaf blades. The blades are hairy on the lower surface or are rarely hairless. The basic flowering units or spikelets are arranged in a spike 4-7 cm long (Fig. 2). The spike has a jointed or segmented cylindrical appearance, the stem constricted at the joints between each segment. The spikelets occur singly in each segment alternating from one side of the flowering stem to the other (Fig. 2). At maturity the segments separate at the joints. The upper and most conspicuous glume of the spikelet is tapered at the apex into an awn or bristle 6-15 mm long.
> BOTANICAL DESCRIPTION An annual (or perennial; Nightingale 2005) grass, decumbent or ascending, with flowering culms 30-90 cm high (Fig. 1), and spreading by stolons. Leaf sheaths hairless or sometimes hairy at base, usually hairy near junction with leaf blade. Leaf blades quite widely spaced along the stem, blades flat or convolute, 3-11 cm long, 0.5-5 cm wide, usually hairy on lower surface or rarely hairless. The inflorescence Fig. 1. Herbarium sheet of Lepturus xerophilus is a solid, more or less cylindrical, solitary spike 4-7 cm long. Spikelets are solitary along each segment of the spike and alternate from one side of the flowering stem to the other. The spikelets are embedded into a recess of the thickened stem (or internode), the joints between each segment is somewhat constricted and the spike can fragment at joints when mature. Each spikelet consists of a prominent upper glume 6-7 mm long, tapered at the apex into an awn or bristle 6-15 mm long, the glume is rough to touch with rows of minute bristles, the lower glume is absent or obscure. The spikelet contains 2 bisexual florets.
FACT SHEET: GRASSES OF CAPE YORK - QUINKAN COUNTRY - Lepturus xerophilus | PAGE 1 of 3 > DIAGNOSTIC FEATURES Cape York Peninsula, it can be distinguished by the Species of this genus that occur in Cape York spikelets occurring alternately along the flowering Peninsula can be identified when flowering by the stem rather than opposite each other as in L. stoloniferous habit (spreading via runners or horizontal geminatus (Fig. 5). The two remaining species which stems which root at the nodes), the solitary spikes with occur in Australia and Far North Queensland have not the spikelets carried on both sides of the spike, and the been recorded for Cape York Peninsula. Lepturus awned glume (Fig. 3). This species can be minutus which has been collected from semi distinguished from Lepturus repens, a common deciduous vine thickets around Chillagoe and Forty coastal species in the region, by: the constrictions Mile Scrub is unique in its extremely small size with between the segments of the spike, the constrictions spikelets less than 3.5 mm long and leaf blades less are more or less absent in L. repens (Fig. 4), and the than 3 cm long. Lepturus copeanus, only collected in much longer awn on the upper glume, 6-15 mm long in Queensland from the Forty Mile Scrub area is L. xerophilus compared with 0-2 mm long in L. repens distinguished from L. xerophilus by its flowering spikes (Fig. 4). From Lepturus geminatus, which is currently produced amongst the foliage not exserted from it. only known in Queensland north of Cooktown on
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Fig. 2. Inflorescence of Lepturus xerophilus Fig. 3. Spikelet of Lepturus xerophilus Fig. 4. Inflorescence of Lepturus repens
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Fig. 5. Inflorescence of Lepturus geminatus
FACT SHEET: GRASSES OF CAPE YORK - QUINKAN COUNTRY - Lepturus xerophilus | PAGE 2 of 3 > NATURAL VALUES An uncommon stoloniferous annual (or perennial).
> HABITAT Only known from a few scattered locations across northern Australia, often associated with limestone in partial shade and in Macropteranthes kekwickii (Bulwaddy) thickets in the Northern Territory.
> LAND MANAGEMENT NOTES This species is considered rare in the region and Australia (Nightingale et al. 2005, Simon & Alfonso 2011).
Fig 6. Map of CYP bioregion showing actual herbarium collections (from BRI and CNS) (solid circle) and site records (open circle) of Lepturus xerophilus. The green shading indicates areas where this species might also be found, based on 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 (2017) Australia’s Virtual Herbarium, Council of Heads of Australasian Herbaria,
For more information: www.capeyorknrm.com.au | 1300 132 262
This project is supported by the Queensland Government Department of Natural Resources and Mines through the Queensland Regional Natural Resource Management Investment Program
FACT SHEET: GRASSES OF CAPE YORK - QUINKAN COUNTRY - Lepturus xerophilus | PAGE 3 of 3