Calyptochloa johnsoniana E.J.Thomps. & B.K.Simon, Austrobaileya 4 (8): 645 (2012)
species nova similar to C. gracillima differing by the longer axillary spikelets (6–6.1 mm versus 3.5–5.5 mm) with a longer upper glume (>4.8 mm versus <4.5 mm); the fertile leaf sheaths (woody abaxially and chartaceous adaxially versus semi-woody to woody for the whole circumference); the fertile culm internodes (bowed adjacent to the spikelets and exserted from the leaf sheath versus culm retained within the leaf sheath); upper glume of the terminal spikelet (scabrid versus pilose). Typus: Queensland. Leichhardt District: Duaringa, December 1976, R.W.Strickland s.n. (holo: BRI [AQ670557]).
Decumbent stoloniferous perennial. Ascending branches to 90 cm tall, copiously branched with 10–20 nodes. Stolons to c. 0.5 m long. Mid-culm leaf blades 20–40 mm long, 3–4 mm wide; adaxial surface with scattered simple and tubercle-based hairs 0.5–2 mm long; abaxial surface with scattered simple and tubercle-based hairs 0.5–2 mm long. Mature fertile leaf sheaths disarticulating, 10–20 mm long, c. 1.5 mm wide near base with wall to 0.3 mm thick on abaxial side, tapering to chartaceous margins; tuberclebased trichomes c. 0.5 mm long between nerves, simple hairs absent; outer margin hairs to 1 mm long. Fertile culm internodes, 13–20 mm long, protruding from leaf sheath and bowing around caryopsis. Sterile leaf sheaths with scattered tubercle-based hairs c. 0.3 mm long. Sterile culm internodes with medium density simple hairs to 2 mm long. Terminal inflorescences on axes 2–5 cm long, 5–6-flowered. Spikelets 4.5–5.5 mm long (without awn), 1.5–1.7 mm wide; lateral pedicels 0.3–1 mm long; ultimate pedicels 4–5 mm long. Lower glume not observed. Upper glume 4.5–5.1 mm long, body with simple hairs to 1.5 mm long at base and scabrid for 60% of length; margins with simple hairs to 2 mm long for 75% of length; apex truncate. Lower lemma 4.5–5.1 mm long, dense tubercle-based hairs to 2.5 mm long for 75% of length; apex obtuse. Upper lemma body 3.1–3.5 mm long, awn to 1–2 mm long. Lodicules c. 0.2 mm long. Upper palea 3–3.3 mm long. Anthers c. 1.6 mm long. Caryopsis not seen. Axillary inflorescences, spikelets single or rarely paired, one sessile and the other pedicellate, pedicel c. 6.5 mm long, enclosed within leaf sheaths with scarsely enlarged basal portion, usually present at 3–5 internodes. Spikelets 6–6.1 mm long (without awn), 1.4–1.5 mm wide. Upper glume 4.8–5.1 mm long, apex obtuse to truncate. Lower lemma 6–6.1 mm long. Upper floret c. 80% of length of lower. Upper lemma body 4–5 mm long, apex with two lateral lobes 0.3–0.5 mm long and awn 3–4.5 mm long. Palea 4–4.5 mm long. Anthers c. 0.3 mm long. Caryopsis cylindrical, c. 4 mm long and 1 mm wide.
Distribution and habitat: The species is known only from the type specimen collected from a red soil plateau near Duaringa The notes on the specimen label do not provide details about the habitat; however, from our existing knowledge it is very likely to be woodland dominated by Acacia shirleyi
(RE 11.7.2).
Phenology: Flowers in December and probably through to March during the wet season.
Notes: Calyptochloa johnsoniana has an overlapping distribution and habitat with C. gracillima subsp. gracillima (Table 1) and C. sp. (Duaringa K.D. Addison 42). Because of the similar growth habit and leaves, C. johnsoniana could easily be confused in the field with C. sp. (Duaringa K.D. Addison 42) which differs by characters including the following: the scabrid ellipsoid cleistogamous spikelets, with woody upper glume and lower lemma, in axillary racemes; the terminal inflorescences being a reduced panicle; the terminal spikelets with upper glume and lower lemma having elliptical cross-section and upper floret equal to the spikelet length.
Conservation status: This species is only known from a single specimen from the type locality near Duaringa. Pending the discovery of additional populations that may extend the geographical range, we recommend that this species should be considered Critically Endangered (criterion B1a-b [IUCN 2001]).
Etymology: The specific epithet is in honour of Dr Robert W. Johnson (1930–2012), former Director at the Queensland Herbarium from 1976–1990.