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The grass genera of the world

L. Watson, T.D. Macfarlane, and M.J. Dallwitz

Pseudocoix A. Camus

~ Hickelia

Habit, vegetative morphology. Perennial. The flowering culms leafy. Culms reaching 40–60 m long; woody and persistent (but weak); scandent (on trees and shrubs); branched above. Rhizomes pachymorph. Leaves not basally aggregated. Leaf blades linear-lanceolate to lanceolate; narrow; 7–9 mm wide (to 15 cm long); not cordate, not sagittate (abruptly attenuate); (presumably) pseudopetiolate; disarticulating from the sheaths (presumably). Ligule present (‘oblong’).

Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets.

Inflorescence. Inflorescence a fascicle of single, bracteate spikelets, ‘pendulous, subspiciform, recalling...(that)...of Coix by its ventricose lemmas’; spatheate; a complex of ‘partial inflorescences’ and intervening foliar organs.

Female-fertile spikelets. Spikelets 15–16 mm long; not noticeably compressed (? ventricose); falling with the glumes. Rachilla prolonged beyond the uppermost female-fertile floret.

Glumes two to several (2–3, membranous); pointed (acuminate or cuspidate); awnless; similar. Lower glume many nerved. Upper glume many nerved. Spikelets with incomplete florets. The incomplete florets proximal to the female-fertile florets. Spikelets with proximal incomplete florets. The proximal incomplete florets 1, or 2 (their lemmas cuspidate, glabrous, shining, becoming ventricose). The proximal lemmas many-nerved; exceeded by the female-fertile lemmas; becoming indurated.

Female-fertile florets 1. Lemmas glossy; becoming saccate (ventricose); decidedly firmer than the glumes; becoming indurated; entire; pointed; awned (long-cuspidate). Awns 1; median; apical; non-geniculate. Lemmas hairless; non-carinate; many-nerved. Palea present; relatively long; awnless, without apical setae; indurated (and inflated); ‘parinervia’; 2-keeled (?- ‘dorsally ‘sulcate’). Lodicules present (large); 3; free. Stamens 6. Ovary apically hairy; with a conspicuous apical appendage. The appendage broadly conical, fleshy. Stigmas 3.

Fruit, embryo and seedling. Pericarp fleshy (apically rostrate); free.

Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous (mainly because of the macrohairs and prickles). Papillae present; costal and intercostal. Intercostal papillae over-arching the stomata (mostly with four papillae over-arching each stomatal apparatus); several per cell (mostly 5–8 in a median longitudinal row, large, circular, thickened). Long-cells similar in shape costally and intercostally; of similar wall thickness costally and intercostally. Mid-intercostal long-cells rectangular; having markedly sinuous walls. Microhairs present; elongated; clearly two-celled; panicoid-type; 60–72 microns long; 4.2–6 microns wide at the septum. Microhair total length/width at septum 10–16.4. Microhair apical cells 28.5–39 microns long. Microhair apical cell/total length ratio 0.48–0.54. Stomata common; 18–21 microns long. Subsidiaries non-papillate. The costal zones with large, bulbous-based macrohairs and occasional prickles. Costal short-cells predominantly paired (but in places the intervening ‘long-cells’ are quite short). Costal silica bodies saddle shaped (predominating), or oryzoid (a few, intergrading with saddles); not sharp-pointed.

Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with non-radiate chlorenchyma; with adaxial palisade; with arm cells; with fusoids. The fusoids external to the PBS. Leaf blade adaxially flat (except for the midrib). Midrib conspicuous; with one bundle only. The lamina symmetrical on either side of the midrib. Bulliforms present in discrete, regular adaxial groups (between the laterally adjacent pairs of fusoids); in simple fans. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present (with all the bundles); forming ‘figures’ (most bundles with anchors). Sclerenchyma all associated with vascular bundles.

Classification. Watson & Dallwitz (1994): Bambusoideae; Bambusodae; Bambuseae. Soreng et al. (2015): Bambusoideae; Bambusodae; Bambuseae; Hickeliinae. 1 species.

Distribution, phytogeography, ecology. Madagascar.

Mesophytic.

References, etc. Leaf anatomical: this project.


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Cite this publication as: ‘Watson, L., Macfarlane, T.D., and Dallwitz, M.J. 1992 onwards. The grass genera of the world: descriptions, illustrations, identification, and information retrieval; including synonyms, morphology, anatomy, physiology, phytochemistry, cytology, classification, pathogens, world and local distribution, and references. Version: 13th November 2017. delta-intkey.com/grass’.

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