320 THE BKOOMRAPE FAMIIA. [Orobanche. 



of green leaves at once distinguishes it from all British species of that 

 family. 



Calyx deeply divided into 2 or 4 pointed sepals 1. Oeobanohe. 



Calyx with 4 broad, short teeth or lobes 2. Lathilea. 



I. OROBANCHE. BROOMRAPE. 



Calyx divided to the base on the upper side, and often also on the 

 lower side, so as to form 2 lateral sepals, either entire or 2-cleft, either 

 distinct from each other, or more or less connected at the base on the 

 lower side, and sometimes on the upper side also by the intervention of 

 a fifth lobe, and always pointed. Habit and other characters those of 

 the family. 



It is the principal genus of the Order, extending over the whole of 

 its geographical range. The species are in general difficult to charac- 

 terise. Some appear to thrive only on the roots of one species, or at 

 most two or three closely allied ones, whilst others will grow on a great 

 variety of plants of the most remote natural affinities. But as the par- 

 ticular stock the plant feeds on may occasion some modification in the 

 habit of the parasite, it is in many cases a matter of great doubt whether 

 the differences observed are owing to this circumstance or to real specific 

 distinction. It is not therefore improbable that some of the species 

 here adopted, although much less numerous than those usually dis- 

 tinguished, may on a more careful observation prove to be mere varieties 

 of each other. 



One bract only under each flower. Plant with little or no blue. 

 Stout plant, 1 to 3 feet high, with numerous flowers in a 

 dense spike. 

 Plant dingy-brown, on shrubby Leguminosce. Stamens 



glabrous below 1.0. major, 



Plant more or less yellow, on Centaurea and other herbs. 



Stamens hairy below 4. 0. elatior. 



Plant seldom above a foot high. Spike short, or with the 

 lower flowers distant. 

 Plant of a dingy-brown, or with a reddish tint. Tube of 

 the corolla broad. 

 Calyx of 2 entire or unequally divided sepals. Plant 



red-brown, on Thyme 3. 0. rubra. 



Calyx of 2 equally divided sepals. Plant light or dark- 

 brown, on Galium .2. 0. caryophyllacea. 



Plant of a light yellowish-brown or purplish, the flowers 

 often tinged with blue. Tube of the corolla narrowed 



above the base 5. 0. minor. 



Three bracts to each flower, one underneath, and a small {one 

 on each side. Plant often bluish. 

 Stem always simple. Calyx 5-toothed or -lobed . . . 6. 0. ccerulea. 

 Stem often branched. Calyx 4-toothed or -lobed . . . 7. 0. ramosa. 



1. O. major, Linn. (fig. 718). Great B. — This, our largest species, 

 is first of a pale yellow, but soon assumes in every part a dingy 

 purplish-brown. Stem simple, stout, from 1 to 1J or 2 feet high, 

 much thickened at the base, with lanceolate scales, which are much 

 shorter and broader at the base of the plant. Flowers closely sessile, 

 with 1 bract to each, forming a dense spike at least half the length 

 of the whole plant. Calyx more or less deeply divided into 2 or 4 

 lanceolate lobes. Corolla f to 1 inch long ; the tube nearly as broad 

 as long, curved with a very oblique limb ; the upper lip entire or 

 shortly 2-lobed, the lower one 3-lobed, with the middle lobe usually, 



