280 



THE POPULAR EDUCATOR. 



LESSONS IN BOTANY. XXXII. 



SECTION LXXXV. MALVACEAE, OR MALLOW- WOETS. 



Characteristics : Calyx free; valvate in aestivation; petals 

 hypogynous, ordinarily slightly joined together at the base ; 

 contorted in aestivation ; stamens indefinite, monadelphous, 

 with nni-locular anthers ; seed dicotyledonous ; embryo curved ; 

 leaves alternate, stipulate. 



Stem herbaceous or ligneous, usually supplied with radiating 

 hairs ; flowers complete, regular, axillary, solitary, or fasciculate, 

 or in a cyme ; pollen in large grains, globular, hispid ; carpels 

 ordinarily numerous, some- 

 times five ; verticillate around 

 a prolongation of the floral 

 axis, sometimes agglomerated 

 into a capsule, either free or 

 partially coherent. Ovules 

 inserted into the central angle 

 of the cells, ascendant or 

 horizontal, curved. 



The styles are free above. 

 Fruit sometimes formed of 

 many shells coherent by their 

 margins to a variable extent ; 

 sometimes a loculicidal capsule 

 with septiferous valves, some- 

 times indehiscent, dry, or 

 fleshy. 



The cotyledons are bent or 

 mutually twisted. Albumen 

 fleshy or none. 



The Malvaceae abound in the 

 tropics, their number dimi- 

 nishing towards either pole ; 

 their chief property depends 

 on a mucilage which abounds 

 in the greater number, whence 

 the Malvaceae are celebrated 

 for their emollient properties. 

 In certain species there exists, 

 in addition to the mucilage, a 

 free acid, generally the oxalic, 

 the presence of which causes 

 them to be refrigerant, antibi- 

 lious, and antiscorbutic. The 

 seeds contain a fixed oil. Some 

 species possess tenacious fibres, 

 others seeds which are covered 

 with a substance resembling 

 wool. 



Among the indigenous spe- 

 cies of this tribe the marsh 

 mallow (Althcea officinalis, Fig. 

 240) is most common. 



The plants of the Cotton 

 sub-family (Gossypium, Fig. 

 241, 242), which belongs to this 

 natural order, are indigenous 

 to Asia and America. Many 

 species are now cultivated on 

 a large scale in every part of 

 the intertropical zone. The 

 laniferous material which en- 

 velopes the seeds is the sub- 

 stance cotton. It has been known and used in Egypt from 

 times of great antiquity, and is now distributed over the whole 

 world. Several remains of Greek literature have been handed 

 down to us written on cotton. Cotton seeds yield on expression 

 a fixed oil. useful for a variety of purposes. 



Numerous foreign Malvaceae are now cultivated in Europe ; 

 for example, the Malope trifida, an annual of Northern Africa, 

 the stem of which rises to the height of about two feet, and 

 which bears flowers of a deep-rose colour ; the Kitaibelia, a 

 biennial Hungarian plant, having lobed leaves and white 

 flowers ; the hollyhock, or Althaea rosea, a Chinesa plant, the 

 varieties of which are extremely numerous ; the tree mallow, or 

 Lavatera arborea, a native of France, &c., bearing large leaves 

 and violet-coloured flowers ; and the hemp-leaved althasa 



239. THE INDIAN CKESS (TROP.EOLUJl). 



1 t Section of flower of the tropseolum ; 2, stamen ; 3, lower petal, with 

 a hair- like fringe at base ; 4, upper petal ; 5, fruit ; 6, fruit, with 

 one of the lobes taken away, and another bisected to show seed. 



(Althaea cannabina), a native of various parts of Central Europe, 

 which has purple flowers, and the stem of which yields a good 

 substitute for hemp. Such are a few of the species of this 

 natural order now familiar in gardens. 



SECTION LXXXVL GEEANIACE^E, OK CEANESBILLS. 



Characteristics : Calyx free ; pstals hypogynous or imper- 

 fectly perigynous, in number equal to the sepals or fewer ; 

 equal in Geranium, reduced to four or two in Pelargonium; 

 contorted in aastivation, caducous ; stamens ordinarily double 

 in number to the petals ; bi-serial ; all fertile (Geranium) 



or partly sterile (Erodium, 

 Fig. 243; Pelargonium, Fig. 

 244), filaments partially mona- 

 delphous ; carpels five, applied 

 to the prolongation of the 

 axis, and constituting a five- 

 celled bi-ovulate ovary ; seed 

 dicotyledonous, exalbuminous, 

 curved; cotyledons bent or 

 contorted ; stem herbaceous 

 or ligneous ;. leaves stipulate, 

 opposite ; the upper ones some- 

 times alternate; flowers com- 

 plete, regular, or irregular 

 (Pelargonium), occasionally 

 solitary, arranged sometimes 

 in twos ; " styles joined into a 

 column, which is longer than 

 the floral axis ; ovules ascend- 

 ant, at first curved, then demi- 

 reflexed. 



Species of this natural order 

 are chiefly found in the extra- 

 tropical regions, more espe- 

 cially at the Cape of Good 

 Hope; they contain tannic 

 and gallic acids, on which ac- 

 count they were formerly em- 

 ployed as astringents in medical 

 practice. The Pelargoniums 

 contain a volatile oil, which 

 imparts to them a very power- 

 ful but at the same time agree- 

 able odour. The Pelargonium 

 roseum and Pelargonium ca,pi- 

 tatum yield an essence possess- 

 ing the odour of roses, which is 

 sometimes employed as a ma- 

 terial wherewith otto of rosea 

 is adulterated. 



SECT. LXXXVII. BALSAMI- 

 NACE.2E, OR BALSAMS. 

 Characteristics : Sepals free, 

 unequal, petaloid; petals five 

 hypogynous, unequal; stamina 

 five ; carpels five, united to 

 form a five-celled ovary; ovules 

 superior, pendent, reflexed ; 

 capsule five-celled, five-valved, 

 dehiscent; seed dicotyledo- 

 nous, exalbuminous ; embryo 

 straight ; stem herbaceous, 

 succulent ; flowers axillary. 



The Balsamincxece are for the most part natives of temperate 

 and tropical Asia. The genus Impatiens, so called on account 

 of the elasticity of its seed-capsules, which, on being touched, 

 dart out the seeds to a considerable distance, has furnished 

 numerous varieties to horticulture. The common balsam plant, 

 Impatiens balsamina, is an annual, a native of India, now 

 rendered double by culture, and furnishing innumerable varieties. 

 The Impatiens repens is a Cingalese species, the representation 

 of which is subjoined (Fig. 245). It has only been recently in- 

 troduced into European culture. 



SECTION LXXXVIIL TROP^OLACE^E, OE INDIAN CEESSES. 



Characteristics : Calyx five-partite, bi- labiate, petaloid ; petals 



five, unequal, inserted at the base of the calyx; stamens eight, 



