AGRIMONLA 



AILANTHUS 



37 



odorata, Mill. Lfts. narrower than in A. Eupatoria; 

 leaflets pubescent : lobes more deeply crenate-dentate : 

 petals more than twice as long as the calyx. Italy. Oc- 

 casionally cult, in Am. j. B. KELLER and W, M. 



51. Ageratum conyzoides. 



AGROFfrRUM (Greek for field and wheat). Graminece. 

 Perennials or annuals, with leaf-blades flat or convo- 

 lute : spike terminal, usually stiff ; spikelets large, 3-8- 

 fld., compressed, sessile at each joint of the simple 

 spike, the side of the spikelet placed next the axis. 

 Species about 30. Temperate regions of Amer. and En. 



repens, Beauv. QUACK GRASS. COUCH GRASS. 

 QUICK GRASS. QUITCH GRASS. A smooth, pale green 

 or glaucous perennial, very variable, with the in- 

 ternodes of the rootstock long. In many places it 

 has become one of the worst weeds, spreading in- 

 veterately by its underground stems. Fig 53. It 

 may be destroyed by constant and thorough tillage. 

 Often valuable to hold loose lands. Considered by 

 some stock raisers as a valuable hay grass. 



AGROSTEMMA. See Lychnis. 



AGROSTIS (agros. field ; the place of growth). 

 Graminece. BENT GRASS. A genus containing many 

 useful grasses for lawns, pastures and bouquets. Pani- 

 cles variable, usually spreading : 

 spikelets very small, awnless or oc- 

 casionally a short awn present. 

 Species about 100, distributed over 

 the entire globe ; about 9 useful in 

 cult. Some species are much con- 

 fused with Aira. In Agrostis the 

 spikelets are 1-fld.; in Aira 2- to 

 several-fld. 



A. Spik< /f/.s- about 1 line long : panicle-branches short. 



Perennial lawn and pasture grasses. 



B. A loili'Hx spikelets. 



alba, Linn. CREEPING BENT GRASS. A well known per- 

 emiiiil, creeping or stolonit'erous, 1-3 ft. : sheaths 

 smooth: leaf-blade linear or narrowly lanceolate, 4-8 in. 

 long, scabrous : ptmicle open, 4-10 in. long, the branches 

 sometimes widely spreading : spikelets about 1 line 

 long: ligulal-4 lines long. Suitable for meadows, pas- 

 ture mixtures, or exclusively for lawn-making. 



Var. vulgaris, Thurb. (A.vuh/clris, With.). RED-TOP. 

 FINE BENT GRASS. Distinguished from the type by 

 the smaller ligule, which is truncate, and less than 1 

 line long. Commoner in cult, than the type. 



Var. stolonifera, Linn. (A . stolonifera, Linn.). Panicle 

 contracted linear; culms extensively creeping or stolo- 

 niferous : ligule 1-4 lines long. 



BB. Awned spikelets. 



canina, Linn. BROWN or DOG'S BENT GRASS. RHODE 

 ISLAND BENT GRASS. Slender, creeping, 1-2 ft. : panicle 

 pyramidal, 4-6 in. long : spikelets near the ends of the 

 branches, very small, 1-9 of an in. long: small bent awn 

 on back of flowering glume. Int. from Eu. Makes a 

 close sod. 



AA. Spikelets about % line long; panicle-branches long 

 and hair-like. Annual ornamental grasses. 

 B. Culms, Ivs. and panicle-branches smooth. 



nebuldsa, Boiss & Reut. (A. capilldris, Hort. ). CLOUD 

 GRASS. Fig. 54. A low grass, with extremely delicate, 

 feathery-like panicle and small spikelets: Ivs. few and 

 very small. Spain. Very useful for vases and bouquets 



minutifldra, Hort. Very similar to A. nebulosa, but 

 smaller, with fewer Ivs. and shorter panicles. Useful 

 for vases and bouquets. 



BB. Culms, Ivs. and panicle-branches scabrous. 



scabra, Willd. ROUGH-BENT. TICKLE GRASS. FLY- 

 AWAY GRASS. HAIR GRASS. SILK GRASS. Hair-like, deli- 

 cate, with widely spreading, capillary panicles, which 

 at maturity break away from the culm and fly about in 

 the wind : spikelets very small, clustered at the ends of 



13. Creeping stem or "root "of quack-grass. 



the branches. Before panicle expands it is often sold in 

 the vicinity of large towns for dry bouquets. 



A. elegans,Hort.,not Thore, and A.pulchella, Hort. These 

 names are applied by florists to Aira elegans and Aira caryo- 



phyllea, which see. 



P. B. KENNEDY. 



52. Agrimonia Eupatoria (X 3). Flower and bur. 



AGUACATE, ALLIGATOR PEAR, AVOCADO. See 



Per sea. 



AILANTHUS (from its native name Ailanto, meaning 

 Tree of Heaven). Simarubacece. Large trees : Ivs. al- 

 ternate, large, pinnate, deciduous : fls. small, in large 

 terminal panicles, polygamous ; petals 5 ; stamens 10 ; 

 fr. consisting of 1-5 distinct samaras. Five species in 

 Cent, and S. Asia and N. Austral. Large, ornamental 

 trees of loose and somewhat spreading habit, with ele- 

 gant, feathery foliage. Very rapid growers. Good for 

 smoky cities. Suckers from the roots. Prop, by seeds 

 and root cuttings. 



glanduldsa, Desf. (A. Japdnica, Hort.). TREE OF 

 HEAVEN. Tree, 60 ft. : Ivs. odd-pinnate, 1^-2 ft. long ; 

 leaflets 13-25, petiolulate, ovate-lanceolate, nearly gla- 

 brous near the base, with 2-4 coarse teeth, each with a 

 large gland beneath : fls. greenish: samaras l%in. long. 

 June. China, cult, in Japan. Valuable tree for street 

 planting, much used in the temperate regions and nat- 

 uralized in some localities ; somewhat tender north in 



