|Gerald F. Guala|
Plants perennial; cespitose, with
short, thick, scaly rhizomes. Culms 80-500 cm tall, to 1.5 cm thick,
reedlike, almost woody; internodes solid. Leaves cauline, evenly
distributed, distichous; sheaths with tightly overlapping margins; ligules
composed of a cartilaginous ridge subtending a line of hairs; blades
broad, flat, deciduous at maturity, margins not cartilaginous. Inflorescences
terminal, plumose panicles, 30-80 cm, exceeding the upper leaves; disarticulation
above the glumes and between the florets. Spikelets laterally compressed;
florets (2)4-10, bisexual, lowest florets sometimes only an empty lemma;
rachilla internodes glabrous. Glumes 2, subequal, shorter than
the lemmas, narrowly ovate, glabrous, membranous, 1-veined, acute; calluses
obtuse, pilose; lemmas narrowly ovate, thinly membranous to hyaline,
3-veined, midveins glabrous, margins and lateral veins long pilose on the distal
2/3, apices bifid, shortly awned from between the teeth; paleas shorter
than the lemmas, hyaline, 2-keeled. x = unknown, frequently reported as
10. Named after A.A. Reynaud, a French surgeon and botanist, who was already
honored by Reynaudia, a genus of grasses
from Cuba; hence the anagram Neyraudia.
Neyraudia is a genus of 2-4species from the tropics of the Eastern Hemisphere. One Asian species is established in Florida. It differs from the other species in the genus in having a sterile lemma at the base of the spikelets. Reports of Neyraudia arundinacea occurring in the Flora region have not been substantiated.
Neyraudia is often mistaken for Phragmites, but that genus has villous rachilla internodes and glabrous lemmas.
1. Neyraudia reynaudiana (Kunth) Keng ex Hitchc.
Burma Reed, Silk Reed
Culms 0.8-3.8(5) m tall, 0.2-1.2 cm thick, often branching above the base. Sheaths glabrous, indurate at maturity; ligules both adaxial and abaxial; blades (7)25-89 cm long, 0.3-2.3 cm wide, auriculate, glabrous abaxially, sparsely hirsute adaxially, adaxial collar area lanate, hairs 2.2-7.2 mm, forming a conspicuous white tuft. Panicles 35-73 cm, longest branches 10-28 cm. Spikelets 4.3-9.5 mm; florets (3)5-10, basal floret in each spikelet reduced to an empty lemma. Glumes 0.5-0.8 mm wide; lower glumes (1.3)1.5-3.1 mm; upper glumes (1.6)2-3 mm; basal lemmas 2.5-4.2 mm; fertile lemmas 3-4.4 mm long, 0.9-1 mm wide, pilose on the lateral veins, otherwise glabrous or minutely papillate; awns about 3 mm, exceeding the bifid lemma apices by up to 1.5 mm; paleas 2.4-3 mm; anthers 3, 1.2-1.7 mm. Caryopses 1.5-3 mm, brown. 2n = 40.
Neyraudia reynaudia is an Asian species that was introduced at Chapman Field, U.S. Department of Agriculture, Coral Gables, Florida, probably from PI #39681, in 1915. It is now a troublesome weed in that state, growing in a variety of habitats from marshy areas to dry pinelands.