showy eastern species are the Weigelas of 

 our modern gardens. [G. D.] 



DIFFUSE. Spreading widely. 



DIGITALIFORM. Like campanulate, 

 hut longer and irregular, as the corolla of 

 Digitalis. 



DIGITALIS. A genvis of Scrophulariacece, 

 represented in this country hy the well- 

 known Foxglove ; which is the badge of 

 the Farquharsons. The genus consists of 

 several species, which are biennials or 

 perennials, with flowers having a calyx 

 deeply divided into five unequal segments ; 

 an irregular tubular corolla, the tube of 

 which is distended in the middle, the limb 

 four or five-lobed, the lowest lobe the 

 longest ; four concealed stamens ; and the 

 f ruit a capsule opening by two valves. 



D. purpurea, the common foxglove, is a 

 well-known ornament of woods and road- 

 sides in this country and the central parts 

 of Europe. It has an erect stem three to 

 four feet high, marked with a few longitu- 

 dinal ridges and covered with greyish 

 down ; the leaves are alternate, ovate- 

 lanceolate or oblong, covered with down, 

 especially on the under surface, their mar- 

 gins crenate or divided into small rounded 

 lobes, and the base tapered gradually into 

 the leafstalks. The raceme is at the ex- 

 tremity of the stem, and consists of a 

 number of flowers each protected by a 

 bract, and all drooping on one side of the 

 stem ; the corollas are irregularly bell- 

 shaped, and upwards of an inch in length, 

 ] and of a pinkish-purple colour, marked in 

 j the interior with circular dark spots, which 

 : are interspersed among a number of deli- 

 | cate light-coloured hairs. This plant from 

 its stately beauty is cultivated in shrub- 

 ' beries and gardens, where likewise a va- 

 j riety with white flowers may be frequently 

 observed. In cultivated plants there fre- 

 quently occurs a malformation, wbereby 

 some one or two of the uppermost flowers 

 become united together, and form an erect, 

 regular, cup-shaped flower, through the 

 centre of which the upper extremity of the 

 stem is more or less prolonged. All parts 

 of this plant possess powerful medicinal 

 properties, which are due to an extremely 

 poisonous substance called digitalin. In 

 medicine the leaves are the parts used, in 

 the form of tincture and infusion. The ef- 

 fects of this drug are various and remark- 

 able; that most frequently observed is a 

 lessening of the force and frequency of the 

 pulse. This occasionally takes place to a 

 dangerous degree, and more than one in- 

 I stance is recorded, of a patient under the 

 ; influence of this medicine, having died im- 

 mediately on making a sudden effort to 

 change his posture. Theheart.enfeebledby 

 i the drug, has been unequal to the fulfll- 

 ; ment of its functions under the increased 

 requirements made upon it by the change 

 in position. Hence, although it may be, 

 and is sometimes used in large doses with 

 impunity, its action must always be watch- 

 ed with great care, the more particularly as 

 occasionally when employed in small but 



frequently repeated doses dangerous symp- 

 toms accrue. Foxglove likewise acts as a 

 diuretic, and in large doses causes vomit- 

 ing, purging, and fainting. It is now most 

 frequently employed in certain cases of 

 dropsy and of heart disease with great 

 benefit, though its use demands care and 

 vigilance on the part of the practitioner. 

 Lately it has been recommended in large 

 doses in delirium tremens. 



Several other species are grown in gar- 

 dens, such as D. grandiflora and P. lutea, 

 with yellow flowers, and D.ferruginea with 

 brown flowers, but none rival our indige- 

 nous foxglove in beauty, though they may 

 do so in their poisonous qualities. [M.T.M.] 



DIGITARIA. A genus of grasses belong- 

 ing to the tribe Panicew, distinguished by 

 the inflorescence being in fingered spikes ; 

 spikelets in pairs, on one side of the flat- 

 tened rachis, awnless, one-flowered with 

 an inferior rudiment of a second ; seed 

 invested with the hardened pales. This 

 genus is nearly allied to Panicum, under 

 which all ' the species are described by 

 Steudel. They are mostly natives of the 

 | middle and south of Europe, one, P. humi- 

 ! fusa, reaching to the southern counties of 

 i England. [D. M.] 



DIGITATE. When several distinct leaf- 

 ' lets radiate from the point of a leaf-stalk. 

 DIGITINERVED. When the ribs of a 

 leaf radiate from the top of the petiole. 



DIGITUS (adj. DIGITALIS). The length 

 of the Index finger. 



DIGLOTTIS. A name applied to a Brazi- 

 ! lian shrub of the rue family, characterised 

 i by its bell-shaped calyx ; its corolla of five 

 i partially united petals; its five stamens, 

 three of which are sterile and adherent to 

 the tube of the corolla, while the two fer- 

 tile stamens have flattened filaments, hairy 

 at the top, and anthers whose connectives 

 are prolonged into acute hairy strap-like 

 processes ; ovaries five. [M. T. M.] 



i DIGRAMMARIA. A genus of polypo- 

 diaceous ferns proposed by Presl, and 

 figured by him in his Tentamen Pteridogra- 

 phice, but somewhat doubtful as to its 

 identity, no fern with indusia such as he 

 describes being known to possess venation 

 such as he figures. Some regard Callipteris 

 ambigua as the plant intended by Presl ; 

 while others consider it to be the plant he 

 afterwards named Heterogonium, which 

 latter view we adopt. This fern has linear 

 oblong naked sori, borne on the two 

 branches of the forked veins, and looking 

 like double lines of spore-cases united 

 below : hence appropriate to the name. 

 The veins too are arcuate, forming costal 

 areoles, with free marginal venules as in 

 Presl's figure. [T. M.] 



I DIGRAPHIS. A genus of grasses be- 

 ; longing to the tribe Phalaridece, and now 

 ' generally referred to Phalaris. [D. M.] 



i DILIVARIA. A small genus of Acan- 



thacece, containing probably not more than 



, three species, erect shrubs, natives of 



