Najas malesiana W.j.de Wilde

Species

Angiosperms > Alismatales > Hydrocharitaceae > Najas

Characteristics

Up to 15 cm, lower internodes 1-3 cm by 0.5-0.8 mm. Leaves (1.25-)2(-2.5) cm by (0.4-)0.5-0.7(-0.9) mm, flat, apex obtuse or slightly acute (blade c. 3 mm below the tip 0.25-0.5 mm wide); margin on either side with (20-)25-30(-50-60) inconspicuous teeth, mainly consisting of the spine-cell; dorsal surface without spines; spine-cells (0.05-)0.1(-0.25) mm, (dark) brown; midrib c. 0.05 times as wide as the blade, cavities occupying up to half the width of the blade, often with distinct septa. Sheaths (1.5-)2-2.5(-3) by 1-2.5 mm, on either side with (2-)6-14 spines, 0-4 spines on the inner edge of the auricle; auricles long-triangular or linguiform, sometimes falcate, 0.5-0.8(-l.l) by 0.3-0.8 mm, entire (rarely shallowly lobed). Female flowers often up to 3 together, in different stages, together with one male (often appressed to the female), or male solitary. Male flowers without spathe; anther 1-celled, elliptical-oblong, apically sometimes narrowed, 0.6-1 by 0.15-0.3 mm; 'perianth lobes' often indistinct; 'pedicel' 0.2-0.4, at anthesis c. 1 mm. Female flowers: spathe absent; rarely up to 0.3 mm stalked; (1.2-)1.5(-1.8) mm; ovary 0.4-0.8 by 0.2-0.3 mm; style 0.25-0.5 mm, with 2(-1) stigmas 0.3-0.6 mm. Seeds (0.9-)1-1.5 by (0.35-)0.4-0.5 to 1.5-1.8 by 0.5-0.6 mm; testa with 16-26 length-rows of 24-30 subquadrate or 5-6-angular areoles.
More
Submerged, monoecious, slender annual, to 1 m long. Stems 0.5–1.0 mm diam.; internodes not spinescent. Leaves linear-lanceolate, flat, 10–19 mm long, (0.3–) 0.4–0.5 (–0.6) mm wide (including spines), acute; margins serrulate; spines unicellular, 0.05–0.1 mm long; septa visible up to halfway to margin or absent; fibres mostly absent; midrib without spines; sheath auriculate; auricle 0.35–0.65 (–1.15) mm long (including spines), serrulate or lacerate, acuminate, with 3–10 spines each side. Male and female flowers at different nodes, with males more common towards plant apex. Male flowers espatheate, 0.6–1.2 mm long; anther 0.5–0.8 (–1.1) mm long, unisporangiate. Female flowers espatheate, 0.4–1 mm long; ovary 0.4–1 mm long; style and stigma 0.6–0.9 mm long; stigma 2-or 3-lobed. Seed (0.9–) 1.2–1.3 (–3.6) mm long; style base persistent; testa distinctly pitted, with areoles regularly arranged in longitudinal rows of (20–) 30–35 (–40).
Life form annual
Growth form herb
Growth support -
Foliage retention -
Sexuality monoecy
Pollination -
Spread -
Mature width (meter) -
Mature height (meter) 0.15
Root system -
Rooting depth (meter) -
Root diameter (meter) -
Flower color
Blooming months -
Fruit color -
Fruiting months -
Nitrogen fixer -
Photosynthetic pathway -

Environment

In streams and pools often in the forest, in swamp forest (Tjitjadas), more rarely in rice-fields (Setul, Padang), at low and medium altitude, once at 900-1000 m (Padang).
Light -
Soil humidity 10-12
Soil texture -
Soil acidity -
Soil nutriment -
Hardiness (USDA) 8-12

Usage

Uses -
Edible -
Therapeutic use -
Human toxicity -
Animal toxicity -

Cultivation

Mode -
Germination duration (days) -
Germination temperacture (C°) -
Germination luminosity -
Germination treatment -
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Optimum temperature (C°) -
Size -
Vigor -
Productivity -

Distribution

Najas malesiana world distribution map, present in Australia, Bangladesh, Brazil, China, Germany, Indonesia, India, Moldova (Republic of), Myanmar, Malaysia, Philippines, Papua New Guinea, Thailand, and Viet Nam

Conservation status

Najas malesiana threat status: Least Concern

Identifiers

LSID urn:lsid:ipni.org:names:603034-1
WFO ID wfo-0000769530
COL ID 45L24
BDTFX ID -
INPN ID -
Wikipedia (EN)
Wikipedia (FR)

Synonyms

Najas graminea var. angustifolia Najas graminea var. minor Najas malesiana