BOTANY. 185 



three genera and thirty -three species. Trlhe 1. TTypericecB. No glands 

 between tlie stamens. Examples : ^Hypericum, *Asyrnm. Trihe 2. 

 JElodew. Glands or scales alternating with the gronps of stamens. 

 Example : *Elodea. 



Hypericum perforatum is the noxious yellow flowered plant, called St. 

 John's Wort, and common in old fields and pastures. 



Hypericum perforatum {pi. 67, ßg. 3); a, flowering branch ; J, calyx ; 

 e, fruit ; <7, lower half of a leaf magnified. 



Okder 188. AuKANTiACE^, the Orange Family. Calyx nrceolate or 

 campanulate, short, three- to five-toothed, withering. Petals three to five, 

 broad at the base, sometimes slightly coherent ; {estivation imbricated. 

 Stamens equal in number to, or a multiple of, the petals ; filaments flattened 

 at the base, distinct or combined into one or more parcels ; anthers erect. 

 Thalamus enlarged in the form of a hypogynous disk, to which the petals 

 and stamens are attached. Ovary free, multilocular ; style one ; stigma 

 thickish, somewhat divided. Fruit a hesperidium, having a spongy, 

 separable rind, and pulpy, separable cells. Seeds anatropal, attached to the 

 axis, solitary, or several, usually pendulous, having the chalaza and raphe 

 usually well marked ; perisperm ; embryo straight ; cotyledons thick and 

 fleshy. Trees or shrubs, usually conspicuous for their beaut}", with 

 alternate, often compound leaves, whicli are articulated with a nsually 

 winged petiole. They abound in the East Indies. There are twenty 

 genera and nearly one hundred species enumerated. Tribe 1. Limonea'. 

 Stamens twice as many as the petals. One ovule only, or two collateral. 

 Example : *Limonia. Tribe 2. Clausenecv. Stamens twice as many as the 

 petals. Ovules two, superimposed. Example : Marraya. Tribe 3. Citreoe. 

 Stamens double or multiple the petals in number. Ovules many, in two 

 series. Examples : Feronia, Citrus. 



Plants of this order are characterized by having receptacles of volatile oil 

 in almost every part. It includes the Orange, Lemon, Lime, Citron, 

 Shaddock, &c. Citrus vulgaris yields the bitter or Seville orange. Sweet 

 oranges are derived from Citrus aurantiura. The best come from the 

 Azores. A single tree has been known to produce 20,000 oranges. Citrus 

 limonum supplies the Lemon ; C. medica, the Citron ; C, limetta, the Lime ; 

 C, decumana, the Shaddock. Oil of Bergamot is the volatile oil from the 

 rind of the Bergamot, a variety of the Lime. Extensive groves of Orange 

 trees are found in East Florida, south of latitude 29° 30', 



Citrus medica, the Citron {jyl. 07, fig. 5); «, a flowering branch; 5, 

 stamens ; c, a single bundle of stamens ; ^, anther ; <', pistil ; y, cross-section 

 of fruit ; </, A, seed. 



Order 189. Olacacejs, the Olax Family. Calyx small, gamosepalous, 

 entire or toothed, often becoming finally large and fleshy ; a'stivation 

 imbricated. Petals three to six, hypogynous, free, or adhering in pairs by 

 means of the stamens ; {estivation valvate. Stamens hypogynous, some 

 fertile, others sterile ; the former three to ten, alternate with the petals, the 

 latter opposite to the petals ; filaments compressed ; anthei-s innate, 

 bilocular, with longitudinal dehiscence, Ovarv one- to three- or four-celled ; 



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