LESSONS IN BOTANY. 



345 



persistent ; corolla inserted externally to a ring surrounding the 

 base of the ovary, campanulate or imperfectly rotate, occa- 

 sionally funnel-Hluipod, its tube ordinarily furnished with tonguc- 

 like scales alternating with the stamens; limb iivi--j)artitf, 

 imlirii-iiti-d in (estivation j stamens to the number of five having 

 t heir filaments bent inwards during aestivation ; anthers in- 

 trorse ; ovary composed of two carpel* (Fig. 181)). 



The Hydrot>lnjllacece are allied to the Polemoniacece, differing 

 from the plunts of this order in the 

 ntal conformation. They are 

 farther removed from the Borayina- 

 ;i I though originally confounded 

 with this natural order in conse- 

 quence of a certain general resem- 

 blance of inflorescence. 



This family is exclusively Ameri- 

 can, where abundant species are 

 found mingled with Polemoniacece 

 in the temperate regions on this 



reoeptaold or upon a fleshy annulus between the calyx and 

 ovary; stamen* inserted upon the tube of the corolla, four, 

 didynamous, occasionally five, the fifth being sterile, occa- 

 sionally only two ; ovary unilocular ; placenta parietal ; fniit 

 superior or inferior ; seed dicotyledonous, containing little or 

 no albumen. 



The Qetneracece are herbaceous plants, rarely ligneous, usually 

 possessing a tetragonal ramified stem ; leaves generally opposite 

 or verticillate ; devoid of stipule*, 

 simple and almost always irregular 

 in the length of their sides. The 

 flowers are complete ; inflorescence 

 a cyme, corymb, or spike ; calyx per* 

 sistent ; corolla tubular, or funnel- 

 shaped, campanulate, or labiate; 

 imbricated in aestivation; stamen* 

 with two anthers usually coherent, 

 one or two celled; ovary consist* 

 of two carpels, but is unilocular; 



190. GERARD'S OESNEEA (GESNERA GERAR- 

 DIANA). 191. VERMILION JESCUIKAK- 

 THUS (jESCHINANTHUS MI SI ATI'S). 



side of the Tropic of Cancer, more 

 especiallytowards the western coast. 

 Between the tropics they are rare, 

 and also beyond the Tropic of Capri- 

 corn. The pretty annuals known 

 as nemophilas, the chief of which 

 are the blue nemophila (Nemophila 

 insignis) and the speckled nemo- 

 phila (Nemophila maculata), belong 

 to this natural order. 



One species, the Canadian hydro- 

 phyl (Hydt-ophyllum Canadense), a 

 hardy herbaceous perennial, is em- 

 ployed in North America as a remedy for the bites of snakes, 

 also for erysipelas caused by the contact of a poisonous North 

 American plant, the sumach (Rhus pumil). J/i/.'n ^/n/Hiuu 

 Virginicum, a species now frequent in botanical gardens, has 

 pinnatisect leaves, and white or blue corolla. 



SECTION XLVIII. GESNERACE^E, OB GESNERWORTS. 



Characteristics : Calyx free, more or less adherent to the 

 ovary ; corolla monopetalous, irregular, inserted upon the 



192. MAST-FLOWERED ACHIMEXES (iCHI- 

 MI-NES MI- LIZ FLORA). 193. SCARLET 

 M1TUAHIA (M1T&A&LA COCCI SEA). 



placentae parietal, opposed, one being 

 on the right, the other on the left 

 of the axis of the flower. Ovules 

 reflexed ; style simple. Fruit a 

 berry or a capsule. Seeds pendent 

 or horizontal (Fig. 190). 



The Gesntracca are, for the moft 

 part, inhabitants of the new conti- 

 nent, especially towards the equa- 

 tor. Some are epiphytes attaching 

 themselves to the trunks of trees, 

 A few of this natural order are 

 found in tropical India, especially 

 I in the islands of the Indian Archipelago, and on the southern 

 slopes of the Himalaya Mountains. 



Those two families, although considerable in the number of 

 their species, offer but little of importance in respect of useful 

 properties. Columned seandfns, a little shrub of India, bearing 

 pretty blue flowers, is cultivated in our hot-houses. Many other 

 species of Gesneracea are in favour amongst cultivators; for 

 example, the jEschinanihus winiatuf, or vermilion sxchmanthua 

 (Fig. 191 ), and the Chirita Moonii, or Moon's chirita, from Ceylon, 



