326 Minnesota Plant Life. 



of which Minnesota species are known. Many of the faniiHes 

 are smaH exotic groups of plants, hut among them are some 

 important economic varieties. The tea-plant, a member of the 

 tea famil\. culti\atc(l in Japan. C'liina and C'e}lon, is classified 

 here, — also the cami)hor plant, the marcgravias, the tamarisks, 

 the passion-flowers and the begonias. The families represented 

 in Minnesota are the St. John's-worts, with about a dozen 

 species, the rock-roses, with three or four species, and the vio- 

 lets, with about twenty sj^ecies. 



St. John's-worts. The St. John's-worts are herbs with oppo- 

 site lea\'es. which are always marked with glandular dots or 

 small black specks. The flowers are borne in panicles or cymes 

 at the apex of slender stems. In each flower there are five sepals 

 and five petals, with a number of stamens sometimes united 

 into clusters. The ovarv is one-chaml)ered, with from three to 

 five interior longitudinal ridges, along wdiich the numerous seed- 

 rudiments are attached. At the top of the capsule, which is 

 generallv ])yramidal-o\-oid in form, from three to six separate 

 stigmas are borne. In some c^f the Minnesota \arieties the 

 longitudinal interior crests of the fruit-rudiment project clear 

 to the centre, thus making a three- to five-chanfl)ered capsule. 

 The flowers are regular in appearance. The difl^erent varieties 

 of St. lohn's-worts mav l)e recognized by their general habit 

 of growth : b\- the sizes and sha])es of the leaves; by the char- 

 acter of the flower-cluster, which, as has been said, is either 

 llat-to])])cd or panicled ; and by the cross section of the Iruit, 

 which is, when mature, in all instances a dry capsule — some- 

 times one-chanfl)ered, sometimes three-cluunbered and some- 

 times five-chanfl)ered. In all these the leaves are ovate, slender 

 or elongated. ( )ne \arivt\-. the marsh St. John's-wort. is found 

 onlv in swamps. It may be recognized by its three-carpeled 

 red ca])sule. 



Rock-roses. The rock-roses include three or four plants, of 

 ledges or barren si>il, known as frostweeds. I liidsoiiuis, pin- 

 weeds, beach heathers or false heather>. The frost weed, which 

 is a prcttx' connnon ])lant throughout the stale, is a woody herb 

 one or two feet in height with two kinds of flowers, — some with 

 petaU and clustered in terniin;fl cymes, the others nuich smaller, 

 without ])etal>. almost sessile in the ;ixils of the leaxes. The 



