Poa Aquatica. 
Water Meadow Grass 
POA Lin. Gen. PL. Triandria Digynia. 
Cal. 2*valvis, multiflorus. Spicula ovata : valvulis margine fcariofis acutiufculis. 
Raii Syn. Gen. 27. Herb.® graminifolias flore imperfecto culmifer.e. 
POA aquatica panicula diffufa, fpiculis fexfloris linearibus. Lin. Syjl. Vegetab. p. 97. Sp. Pl. 
p. 98. FI. Suec. n. 2 6. 
POA altiflima, foliis latiflimis, panicula ampliflima, locuftis diftichis multifloris. Haller hijl. n. 1454« 
POA aquatica. Scopoli FI. Carn. n. 105. 
GRAMEN aquaticum paniculatum latifolium, Bauh. Pin. 3. 
GRAMEN aquaticum majus. Ger. emac. 6 . Raii Syn. p. 411. Great Water-Reed-Grafs. Hud/on 
FI. Angi. cd. 2. p. 38. 
RADIX perennis, repens. | 
CULMUS tripedalis, ad fepedalem, ereftus, foliofus, $ 
craflitie culmi arundinacei, fu pe me ubi nudus, $ 
teres, laevis, fubtililfime ftriatus geniculis ^ 
flavefcentibus. v 
FOLIA femunciam aut unciam fere lata, utrinque | 
glabra, tenuiflime ftrjata, carinata, carina $ 
marginibufque afperis, ad balin lolii utrinque ^ 
macula triangularis flava, vagina glabra, <> 
ftriata, carina prominente, membrana brevis | 
obtufa. $ 
<E> 
PANICULA maxima, femipedalis, aut pedalis, ere6la, ^ 
ramofiflima. Y 
PEDUNCULI fubtriquetri, fcabri, fuperne flexuofi. 
t 
S PICULAE lanceolatae, fubcompreflk 6 — 8. floree, | 
colore ex fpadiceo et viridi milio. 
CALYX : Gluma bivalvis, valvulae membranaceae, < 
uninerviee, ovatae, concavae, interiore bre- 
viore et acutiore. 
COROLLA bivalvis, valvulae fubaequales, obtufae, 
exteriore majore, concava, nervofa, ad balin j 
tuberculata, interiore planiufcula. 0 
STAMINA: Filamenta tria, alba, capillaria; An- X 
theR.-e oblongae, utrinque bifidae, flavae aut v 
purpureae. $ 
PISTILLUM: Germen ovatum, glabrum; Styli | 
duo, fuperne ramofi, inferne nudi, paulo in- ^ 
fra apicem prodeuntes. ^ 
NECTARIUM : fquamula parva truncata ad bafin | 
germinis. & 
SEMEN tectum, hinc convexum, ftriatum, inde con - 1 
cavum, pallide fufcum. q 
ROOT perennial, and creeping. 
STALK from three to fix feet high, upright, leafy, 
the thicknefs of a reed liraw, on the upper 
part where it is naked, round, fmooth, very 
finely grooved ; the joints yellowilh. 
LEAVES half an inch and almoll an inch broad, 
fmooth on both fides, very finely grooved, 
keeled, the keel as well as the edges rough, 
the bafe of the leaf on each fide is marked 
with a yellow triangular fpot, the Jlieath is 
fmooth and ftriated, the keel prominent, the 
membrane Ihort and obtufe. 
PANICLE very large, from fix inches to a foot in 
length, upright, very much branched. 
FLOWER-STALKS fomewhat three-cornered, rough, 
crooked above. 
SPICULiE lanceolate, fomewhat flattened, contain- 
ing from fix to eight flowers, variegated with 
green and purple. 
CALYX : a Glume of two valves, the valves mem- 
branous, one-ribbed, ovate, concave, the in- 
nermoft fhorter and more pointed than the 
other. 
COROLLA compofed of two valves, which are nearly 
equal, obtufe, the outer one largeft, con- 
cave, ribbed, with a fmall tubercle at the 
bafe, the inner one nearly flat. 
STAMINA: three, white, capillary Filaments; 
Anthers oblong, bifid at each end, yel- 
low or purple. 
PISTILLUM: Germen, ovate, fmooth; Styles 
two, branched above, naked below, proceed- 
ing from a little below the top. 
NECTARY : a fmall truncated fcale at the bafe of 
the germen. 
SEED covered, convex and ftriated on one fide, con- 
cave on the other, of a pale brown colour. 
The Poa aquatica is one of the largeft as well as the mod ufeful of our graffes ; it conftitutes a great part of 
the riches of Cambridgefhire, Lincolnfhire, and other counties, where draining the land by means of windmills 
has taken place ; immenfe trafts of territory that ufed to be overflown and produce ufelefs aquatics, but which 
ftill retain much moifture, are, by the above procefs, fpontaneoufly covered with this grafs, which not only 
affords rich paflurage for their cattle in the fummer, but forms the chief part of their winter fodder. 
It has a powerfully creeping root, and bears frequent mowing well (we have known it cut thrice in one 
feafon in the vicinity of the Thames) ; hence it is apt to gain the afcendancy over, rather than be overcome 
by other plants. 
' It grows not only in very moift ground, but in the water itfelf : like the Cats-tails, Burr-reed, and feveral 
other plants of that kind, it foon fills up the watery ditches which furround the meadows in which it grows, 
and oc cations them to require frequent cleanfing ; in this refpeft it is a formidable plant, even in flow rivers. 
In the lfle of Ely, they have a particular method of cleanfing the rivers, which are liable to be foon choked 
up by the Arrow-head. Water-lilies, Reeds, &c. by means of an inftrument called a Bear, which is an iron 
roller, in which a number of pieces of iron, like fmall fpades, are fixed ; this is drawn up and down the 
river by horfes, which travel on the banks, and tearing up every plant by the roots, they float and are carried 
away by the ftream. 
The Poa aquatica not only affords fuftenance to cattle, but is a favourite food of the Caterpillar of the 
Gold-fpot Moth ( Phaleena Fejlucx, Lin.) which Linnaeus defcribes as feeding on the Fejluca jluitans, but 
which feeds with us chiefly on this grafs : the Moth proceeding from this larva, is one of the moft beautiful 
which this country produces ; the Caterpillar being fmooth and of a green colour, is not eafily diftinguifhcd 
from the grafs on which it feeds ; when full-grown, it ufually bends down the top of one of the leaves, and 
underneath it, makes a thin fpinning, in which it changes to chryfalis ; this fpinning, from its whitenefs, is 
eafily difcovered ; but we mull apprize our readers, that thefe Caterpillars are not very numerous, and that 
they will be fortunate if they find one or two after a long fearch ; the Moth, Caterpillar, and Chryfalis, are 
figured in Albin’s Englilh Infe£ls ; but a much better painting of the Moth may be feen in Roesel, Tom. 1. 
Tab. 30. We have generally found them at the commencement of harveft, when the wheat has been in fheaf- 
the Moth comes forth in a week or two. 
We obferved in the lfle of Ely, a much larger Caterpillar, when full-grown, nearly the fize of the Ph. 
Potatoria, hairy and very beautiful, not uncommon on this grafs; but not having the proper convenience 
for breeding it, we are as yet unacquainted with the Moth it produces, but fufpeft it will prove a non-defcriot. 
The Poa aquatica flowers as late as Auguft and September. . 1 
