500. 



BETULA 



BIENNIALS 



p. 26. R.F.G. 12:1279. B. intermedia, Thomas (B alpestris, 

 Fries. B. pubesccnsxB. nans). Shrub: Ivs. orbicular or ovate, H~ 

 1 in. long, crenate-errate, usually pubescent while young, and often 

 glutinous, finely glabrous: strobiles oblong: lateral lobes of scale up- 

 right and usually shorter than the middle one. N. Eu. Natural 

 hybrid; very variable. B. Jdckii, Schneid. (B. lenta Xpumila). 

 Shrub: bark of the odor of B. lenta: Ivs. usually obovate, 1-2 in. 

 long, usually with about 7 pairs of veins: strobiles oblong, H-Jiin. 

 long; lateral lobes of scales spreading, somewhat shorter than the 

 middle one. Originated at the Arnold Arboretum. G.F. 8:245. 

 B. ken&ica, Evans. Allied to B. occidentalis. Tree, to 40 ft. : bark 

 grayish white or light reddish brown: branchlets glabrous, not or 

 slightly glandular: Ivs. ovate, 1 H-2 in. long, cuneate or rounded at 

 the base, irregularly, often doubly serrate, glabrous: strobiles cylin- 

 dric-oblong, about 1 in. long, glabrous. Alaska. S.S. 14:723. B. 

 Karhnei, Schneid. (B. papyrifera Xpendula). Intermediate between 

 the parents. Tree: branchlets sparingly pubescent : Ivs. ovate, 2-3 Yi 

 in. long, usually truncate at base, acuminate; rather finely and 

 doubly serrate: scales of strobiles simitar to those of B. papyrifera. 

 Origin unknown. B. luminifera, Winkl. Allied to B. alnoides. Lys. 

 ovate, subcordate at the base, serrate with acuminate teeth, 3-5 in. 

 long: strobiles solitary. 2-3 in. long. Cent. China. W. 92. B. Med- 

 wedjewii, Regel. Allied to B. utilia. Tree: young branchlets hairy: 

 Ivs. broadly ovate to obovate, 2-3 in. long, rounded or sometimes 

 subcordate at the base, short-acuminate, glabrous or pubescent on 

 the veins beneath: strobiles cylindric-oblong, 1-1 % in. long; wings 

 of nutlet often 4 times narrower than its body. Caucasus. Gt. 36, 

 p. 384. B. occidentilis, Nutt., not Hook.=B. fontinalis. B. Pur- 

 piisii, Schneid. (B. lutea Xpumila). Shrubby or small tree: Ivs. 

 oblong-ovate, 1-2 in. long, with 7-9 pairs of veins, soft-pubescent 

 beneath. Intro, to Eu. from Mich. B. Radde&na, Trautv. Tree: 

 Ivs. ovate-pubescent on the veins beneath, with 6-7 pairs of veins, 

 1-2 in. long: strobiles oblong, upright, 5i>n. long; wings as broad as 

 nutlet. Caucasus. Gt. 36, p. 384. B. rhombi/dlia, Nutt.=B. 



ALFRED RBHDEB. ' 



BIARUM (old and obscure name). Incl. Ischarum. 

 Aracese. Dwarf, tuberous perennials of the same tribe 

 with our native jack-in-the-pulpit. They are hardy in 

 England, but probably are suitable only for pot-cul- 

 ture in the Northern United States. 



Biarums have a spathe which is tubular at the base, 

 mostly with a long limb, and usually a long tail-like 

 spadix; otherwise much as in Arum. They grow a few 

 inches high. Odd. Little known in Amer. A few spe- 

 cies in Eu. and Asia Minor. 



tenuifdlium, Schott (Arum tenuifblium, Linn.). 

 Lvs. linear-lanceolate or spatulate, appearing after the 

 fls. decay: spathe long-acuminate, at length recurved 

 and twisted spirally, about 10 in. long, outside green, 

 streaked purple; inside dull purple, spotted; margins 

 wavy; spadix 15 in. long. Spain. B.M. 2282. 



Pyrdmii, Engler (Ischdrum Pyrdmii, Schott). Lvs. 

 oblong above the middle, narrowing abruptly to a very 

 long petiole, resembling Calla palustris: spathe green 

 outside, shining, velvety purple within, shorter and 

 broader than in B. tubiflorum, at length revolute; tube 

 swelling, connate only at the very base; spadix thicker 

 and shorter. Syria. B.M. 5324. 



Bdvei, Blume. Lvs. similar to B. Pyramii; spathe- 

 tube connate a fourth of its length; blade of spathe 

 longer and more narrowly lanceolate, green outside, 

 dark purple within. Syria, Asia Minor. L H. B. 



BIDENS (Latin, two-teeth, in reference to the awns). 

 Composite. BUR-MARIGOLD. STICK-TIGHTS. TICK-SEED. 

 Annual, or rarely perennial, herbs, mostly American, 

 related to Coreopsis, Dahlia, and Cosmos. 



'Leaves opposite, serrate or incised, often pinnately or 

 ternately divided: heads radiate or discoid; rays yellow 

 or white; disk yellow; involucre double, the outer set of 

 bracts green and more or less foliaceous, the inner of 

 quite different texture and shape, more appressed, 

 thinner, more scarious and striate: achenes flat or 

 angled; pappus of 2-4 stiff bristles or awns, usually 

 retrosely barbed. Plants grown as garden annuals. 

 B. frondosa, a common weed, is the well-known boot- 

 jack bur, or stick-tight. 



A. Achenes obovate or cuneate-oblong, more or less flattened 

 or triangular, the faces uni-coslate: texture of If. medium. 



B. Size of achenes small (1-2 lines long) with firm gla- 



brous margins: inner involucre dark dolled. 

 coronata, Fisch. (Coreopsis aiirea, Ait.). St. 1-4 ft. 

 high, branched above, glabrous or nearly so: Ivs. ter- 



nately or pinnately divided: outer involucre about 

 equaling the dark-dotted inner: achenes dark, very 

 small, 1-2 lines long, narrowly cuneate, 3-angled, mar- 

 gin firm and glabrous; pappus of 2^-4 minute awns and 

 some chaff. S. E. U. S. Very variable. 



BB. Size of achenes larger (2-4 lines long) with hispid 



margins: involucre not doited. 



trichosperma, Brit. (Coredpsis trichosperma, Michx.). 

 St. tall, 2-5 ft. high, glabrous, branched above: Ivs. 

 pinnatifid : outer involucre about equaling the undotted 

 inner: achenes dark, larger, 2j^-4 lines long, cunentc, 

 moderately flat, margin firm, usually pubescent; pap- 



S us of 2 upwardly hispid broad-based awns about y- 

 ne long. E. U. S. Var. tenuif&lia, Brit. Lf.-segms. 

 narrowly linear: achenes 2-3 lines long. 



arist&sa, Brit. (Core6psis aristosa, Michx.). St. 1-4 

 ft. high, branched above, nearly or quite glabrous: 

 Ivs. pinnatifid, often pubescent beneath: outer involu- 

 cre about equaling the undotted inner: achenes olive 

 or brownish, large, 2-4 lines long, broad and very flat 

 1-2^ lines broad, abruptly contracted at summit, 

 margin thin and hispid, often crenulate; pappus awns 

 2, each 1-2 lines long, divergent, stramineous, up- 

 wardly or downwardly barbed, or sometimes entirely 

 wanting. Cent. U. S. B.M. 6462. R.H. 1869:72. 



AA. Achenes linear-spindle-shaped, tapering graduuUy 

 above, angled or costate: texture of If. usually firmer. 



B. Lvs., in part, finely dissected: rays large, golden yellow. 



grandifiora, Balb. St. 1-4 ft. high, branched, gla- 

 brous and 'somewhat glaucous: Ivs. pinnatifid, the 

 divisions either lanceolate and serrate or dissected into 

 narrowly linear divisions: outer involucre about equal- 

 ing the more or less hirsute inner; rays large, golden 

 yellow: achenes 3-6 lines long; awns 2, downwardly 

 barbed, about 1 line long. Mex. A showy plant some- 

 times cult, in Amer. 



BB. Lvs. or their divisions lanceolate to ovate: rays pale 

 yellow or whitish. 



Warszewicziana, Regel. Erect, glabrous perennial: 

 Ivs. simple, or pinnate or rarely bipinnate, the lobes 

 lanceolate or ovate-lanceolate: heads corymbose, the 

 involueral bracts ciliate; petals whitish or yellowish, 

 of medium size: achenes compressed, angular, the 

 angles ciliate. Guatemala. Hardy N. only with pro- 

 tection. 



pildsa, Linn. St. 2-5 ft. high, much branched, nearly 

 glabrous: Ivs. ternate or pinnate, divisions lanceolate, 

 incised-serrate with somewhat rounded teeth: outer 

 involucre about equaling the glabrous or minutely 

 puberulent inner: rays short, 1-3 times as long as the 

 involucre, creamy- white: achenes 4-7 lines long; awns 

 2-4, downwardly barbed, 1^ lines long. Tropics. 

 Sometimes grown in botanic gardens. 



B, dahlioides, Wats. A perennial with dahlia-like tubers. Mcx. 

 G.C. III. 48:226. R.H. 1910, p. 475. 



K. M. WIEGAND and N. TAYLOR. 



BIENNIALS. Plants that bloom a year after the 

 seeds are sown, then make seeds and die. Familiar 

 examples among vegetables are cabbage, turnips, 

 celery and onions, but in warm or long-season climates 

 they become annuals. Even in northern gardens, celery, 

 carrots and beets, if permitted to crowd, will often run 

 to seed the first year. On the other hand, many bien- 

 nials, such as hollyhocks and others, are practically 

 perennial because they self-sow, or multiply by off- 

 shoots, so that there is little danger of losing them. 

 Such cases give rise to discussion as to whether a plant 

 is an annual, biennial, or perennial, but the practical 

 problems are few and simple, and are commonly con- 

 nected with the following favorite flowers: 



Hollyhock (Althxa rosea), snapdragon (AntirrhwMS 

 mujus), English daisy (Ltellis perennis), Canterbury 



