242 



arctic circle, and almost disappearing within the tropics. A few species 

 only are found in such latitudes. In North America they are less abundant 

 than in Europe. Pursh reckons but 22 species in the whole of his Flora ; 

 while the little island of Sicily alone contains 35, according to Presl. 



Properties. Soft, mucilaginous, emollient properties, are the usual 

 characteristics of this order ; some are also said to contain nitre, a proof of 

 which is shewn by their frequent decrepitation when thrown on the fire. 

 Borago officinalis gives a coolness to beverage in which its leaves are steeped. 

 Echium plantagineum, naturalised in Brazil, is used in that country for the 

 same purposes as the Borago officinalis in Europe. PL Usuelles, 25. The 

 roots of Anchusa tinctoria or Alkanet, Lithospermum tinctorium, Onosma 

 echioides, Echium rubrura, and Anchusa virginica, contain a reddish brown 

 substance used by dyers. This matter is thought to be a peculiar chemical 

 principle approaching the resins. 



Examples. Borago, Lycopsis, Anchusa. 



CCXXIII. HELIOTROPICE^. The Heliotrope Tribe. 



HeliotropicE/E, Mart'ms N. G. et Sp. 2. To. and 138. (1828.) 



Diagnosis. Monopetalous dicotyledons, with regular flowers, a supe- 

 rior 4-celled ovarium with solitary pendulous ovules, 5 stamens, and exalbu- 

 minous seeds with plano-convex cotyledons. 



Anomalies. 



Essential Character — Calyx inferior, hypogynous, 5-parted, persistent. Co- 

 rolla hypogynous, monopetalous, regular, with a 5-parted limb, the segments of which are 

 imbricated in aestivation. Stamens arising from the tube t)f the corolla, and alternate with 

 the segments ; anthem innate ; pollen globose. Ovarium entire, 4-celled, with 4 pendulous 

 ovnla ; style terminal, simple ; stigma simple. Fruit drupaceous, separable into 4 pieces, 

 terminated by the persistent style. Seeds pendulous, solitary ; embryo without albumen, 

 with fleshy plano-convex cotyledons and a minute radicle curved downwards and turned 

 towards the hilum. — Half shrubby and herbaceous plants, covered over with asperities. 

 Leaves alternate, simple, without stipulae. Flowers in terminal fascicles, cymes, or 

 corymbs. 



Affinities. Distinguished from Boragineae solely by having a style 

 proceeding from the apex of an undivided ovarium of several cells, by the 

 drupaceous fruit separating in pieces, and the absence of albumen. 



Geography. Common in the hotter parts of South America, the East 

 and West Indies, the north of Africa, and the Levant ; a few are found in 

 the south of Europe and the southern states of America, but none appear to 

 dwell further north than the parallel of 45°. 



Properties. Unknown, except that some of the species are remark- 

 able for their fragrance. Most of them are insignificant weeds. 



Examples. Heliotropium, Preslea. 



CCXXIV. EHRETIACEiE. 



Eh RET I ace /E, Marlius N. (',. et Sp. 2. 13«. (1828.) 



Diagnosis. Monopetalous dicotyledons, with regular flowers, a superior 

 2- or more-celled ovarium with suspended ovules, 5 lobes to the calyx, and 

 albuminous seeds. 



Anomalies. 



