Poa Aquatica. Water Meadow Grass. 



POA Lin. Gen. PL Triandria Digynia. 



Cal. 2-valvis, multiflorus. Spicula dvata : valvulis margine fcariofis acutiufculis. 



Rail Syn. Gen. 27. Herb^e graminifoli^e flore imperfecto culmifer.e. 



POA aquatica panicula difFufa, fpiculis fexfloris linearibus. Lin. Syjl. Vegetal, p. 97. Sp. PL 

 p. 98. FL Suec. n. 26. 



fOA altiffima, foliis latiflimis, panicula ampliffima, locuflis diftichis multifloris. Hallerhift, n. 1454. 



POA aquatica. Scopoli FL Cam. n> 105. 



GRAMEN aquaticum paniculatum latifolium, Bauh. Pin. 3. 



GRAMEN aquaticum majus. Ger.emac.6. Rati Syn. p. 411* Great Water-Reed-Grafs. Hudfori 

 FL Angl. ed. 2. p. 38. 



~ . . - I ' . - — . . i 



RADIX perennis, repens. <> ROOT perennial, and creeping* 



CULMUS tripedalis, ad fepedalem, ere&us, foliofus, | STALK from three to fix feet high, upright, leafy, 

 craffitie culmi arundinacei, fuperne ubi nudus, §■ the thicknefs of a reed ftraw, on the upper 



teres, laevis, fubtiliffime ftriatus ; geniculis | part where it is naked, round, fmooth, very 



flavefcentibus. $ finely grooved ; the joints yellowifh. 



FOLIA femunciam aut unciam fere lata, utrinque | LEAVES half an inch and almoft an inch broad, 

 glabra, tenuiflime ftriata, carinata, carina i fmooth on both fides, very finely grooved, 



marginibufque afperis, ad bafin folii utrinque | keeled^ the keel as well as the edges rough, 



macula triangularis flava, vagina glabra, <f> the bafe of the leaf on each fide is marked 



ftriata, carina prominente, membrana brevis | with a yellow triangular fpot, the Jheath is 



obtufa. <f> fmooth and ftriated, the keel prominent, the 



Jj membrane Ihort and obtufe. 



PANICULA maxima, femipedalis, aut pedalis, erecla, \ PANICLE very large, from fix inches to a foot in 

 ramofiffima. Jj length, upright, very much branched. 



PEDUNCULI fubtriquetri, fcabri, fuperne flexuofi. | FLOWER-STALKS fomewhatthree-cornered,rough, 



^ crooked above. 



SPICULE lanceolatae, fubcompreffae 6—8. florae, | SPICUL^E lanceolate, fomewhat flattened, contain- 

 colore ex fpadiceo et viridi mifto. i ing from fix to eight flowers, variegated with 



I green and purple. 



CALYX: Gluma bivalvis, valvulae membranaceae, <> CALYX : a Glume of two valves, the valves mem- 

 uninerviae, ovatae, concavas, interiore bre- | branous, one-ribbed, ovate, concave, the in- 



viore et acutiore. § nermoft fhorter and more pointed than the 



y other. 



COROLLA bivalvis, valvulae fubaequales, obtufae, |> COROLLA compofed of two valves, which are nearly 

 exteriore majore, concava, nervofa, ad bafin | equal, obtufe, the outer one largeftv con- 



tuberculata, interiore planiufcula. ' a cave, ribbed, with a fmall tubercle at the 



v bafe, the inner one nearly flat. 



STAMINA: FiLAMENTAtria, alba, capillaria; An- ^ STAMINA: three, white, capillary Filaments; 

 THERiE oblongae, utrinque bificlae, flavae aut | Anthers oblong, bifid at each end, yel- 



purpureae. % low or purple. 



PISTILLUM: Germen ovatum, glabrum ; Styli | PISTILLUM : Germen, ovate, fmooth; Styles 

 duo, fuperne ramofi, inferne nudi, paulo in- | two, branched above, naked below, proceed- 



fra apicem prodeuntes. j> ing from a little below the top. 



NECTARIUM : fquamula parva truncata ad bafin | NECTARY : a fmall truncated fcale at the bafe of 

 germinis. J» the germen. 



SEMEN teclum, hinc convexum, ftriatum, inde con- 1 SEED covered, convex and ftriated on one fide, con- 

 cavum, pallide fufcum. cave on the other, of a pale brown colour. 



The Poa aquatica is one of the largeft as well as the moft ufeful of our graftes ; it constitutes a great part of 

 the riches of Cambridgefhire, Lincolnlhire, and other counties, where draining the land by means of windmills 

 has taken place ; immenfe tra&s 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 pafturage 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 

 bv 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 occafions them to require frequent cleanfing ; in this refpecl it is a formidable plant, even in flow rivers. 



In the Hie 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. . r n 



The Poa aquatica not only affords fuftenance to cattle, but is a favourite food of the Caterpillar of the 

 Gcld-fpot Moth {Phalcena Fejlucce, Lin.) which Linn.^us defcribes as feeding on the Fefluca fiuitans, 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 difiinguifhed 

 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 muft 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 Englifh Infeds ; 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 m fheaf ; 

 the Moth comes forth in a week or two. n 



We obferved in the Ifle of Ely, a much larger Caterpillar, when full-grown, nearly the hze of the Ph. 

 Rotatoria, hairy and very beautiful, not uncommon on this grafs ; but not having the proper coavemence 

 for breeding it, we are as yet unacquainted with the Moth it produces, but fufpea it will prove a non-defcnpt. 

 The Poa aquatica flowers as late as Auguft and September. 



