58 



A SYNOPSIS OF THE PLANT KINGDOM 



on inside of the receptacle; ovary inferior, 1-celled, 

 with 3 to many parietal placentae; ovules numerous; 

 style 1; stigmas as many as the placenta;: fruit a berry; 

 embryo straight or curved. 



The Cacti are almost entirely confined to the dry 

 regions of tropical and subtropical America. Mexico 

 is the center of this distribution, but the Cactaceae ex- 

 tend from New York to Patagonia. A species of Rhip- 

 salis has lately been found indigenous in West Africa. 

 The family is related to the Begoniacese, Loasaceae, and 

 PassifloraceaB. The peculiar habit, perianth of many 

 similar parts, many stamens, and inferior 1-celled ovary 

 are distinctive. The Cactaceae is divided into three 

 groups: (1) Cereus group, with receptacle extended in 

 a tube beyond the ovary (perigynous), and no hooked 

 spines; (2) Opuntia group, tube of the receptacle want- 

 ing, hooked spines usually present; (3) Pereskia group, 

 with foliaceous leaves, panicled flowers, and no hooked 

 spines. 



The seeds of Rhipsalis, an epiphytic genus, are often 

 viscid so as to adhere to tree trunks and the like. The 

 ovaries of some Cactacese are imbedded in the tissue 

 of the stem. In this family, the thick stem is a water- 

 storing organ. The flatttened or fluted condition of the 

 stem of most species is probably an adaptation which 

 allows these stems to swell when water is abundant 

 and contract when it is scarce without danger of 

 rupturing the cuticle. The variation in size and form 

 among cacti is very great. The largest species is 

 Carnegiea giganteus of Mexico, candelabra-like, 60 feet 

 high. 



The fruit of Opuntia Ficus-4ndica, now naturalized 

 in the Mediterranean region, is there eaten under the 

 name of Indian fig. Opuntia Tuna of tropical America 

 is the prickly pear, an edible fruit. Opuntia vulgaris of 

 the eastern United States is also eaten under the name 

 of prickly pear or Indian fig. Fruits of Cereus trian- 

 gularis, C. giganteus, and C. Thurberi are much prized. 

 The stem and flowers of C. grandiflorus are used in 

 medicine, producing an action on the heart. Vermif- 

 ugal properties are found in many Cactacese. An 

 alcoholic drink is made by the Mexicans from the sap of 

 species of Cereus. The cochineal insect, a scale insect 

 yielding the well-known dye, cochineal, lives upon spe- 

 cies of Opuntia, Pereskia, and Nopalea, in tropical 

 America. 



The total number of genera of Cactacese which have 

 been described up to the present time is about 70. 

 although Dr. Karl Schumann, who monographed 

 the family in 1899, recognized but 21. Of the many 

 genera described, most are good and will probably 

 stand. A rational and uniform treatment of the family 

 will doubtless show that there are no less than 75 ten- 

 able genera. The total number of names published is 

 something over 3,800. This includes many species that 

 have been transferred from one genus to another. The 

 number of species recognized by Schumann is some- 

 thing less than 700. Many of these species of Schumann, 

 however, are known to be aggregates, and it is not 

 unlikely that there are about 1,200 species in the 

 family. 



The number of genera treated in this work is 35. 

 They are in cultivation in America as odd plants for 

 desert gardens, and as greenhouse curiosities. Many 

 have beautiful showy flowers, those of Cereus grandi- 

 florus (night-blooming cereus) being nearly one foot 

 across, and opening only in the night. 



The reader will find the cacti described in this 

 Cvclopedia under the following names: Acanthocereus; 

 Anhalonium =Ariocarpus; Aporocactus; Ariocarpus; 

 Bergerocactus; Cactus; Carnegiea; Cephalocereus; 

 Cereus; Disocactus; Echinocactus; Echinocereus; Echi- 

 nopsis; Epiphyllum = Zygocactus; Escontria; Hariota; 

 Harrisia; Heliocereus; Hylocereus; Lemaireocereus; 

 Leptocereus; Leuchtenbergia; Lophophora; Mamil- 

 laria; Melocactus = Cactus; Myrtillocactus; Nopalea; 



Opuntia; Pachycereus; Pelecyphora; Pereskia; Per- 

 eskiopsis ; Phyllocactus = Epiphyllum ; Pilocereus = 

 Cephalocereus; Rathbunia; Selenicereus; Schlumber- 

 gera; Wilcoxia; Wittia; Zygocactus. 



Order 44. MYBTIFLOILE 



157. Thymelaeaceae (from the generic name Thyrn- 

 elxa, a Greek name meaning thyme + olive or oil). ME- 

 ZEREUM FAMILY. Fig. 42. Shrubs or trees, rarely 

 herbs: leaves alternate or opposite, simple, entire: 

 flowers bisexual or unisexual, regular, receptacle devel- 

 oped into a long tube which bears appendages in the 

 throat; perianth undifferentiated, often petaloid, parts 

 4-5, imbricated, perigynous; stamens as many as the 

 sepals and alternate with them, or twice as many, or 



42. THYMEI^EACE^E: 1. Daphne, flower. EI-EAGNACE^E: 2. 

 Elffiagnus, a, male flower; 6, bisexual flower; c, floral diagram; d 

 and e, hairs from surface of leaf. LYTHHACE.E: 3. Lythrum, a, 

 flower; 6, trimorphic flowers of L. Salicaria; c, floral diagram. 

 PUNICACH*: 4. Punica, a, flower; b, fruit, upper story; c, fruit, 

 lower story. 



reduced to 2, perigynous; ovary superior, 1-celled, 

 rarely 2-celled; ovule solitary, pendulous; style 1 or 0, 

 stigma 1: fruit indehiscent, a nut, drupe, or berry; 

 rarely a capsule. 



About 37 genera and 425 species are widely distrib- 

 uted over the earth. One species is native in north- 

 western North America. The largest genera are Gnidia 

 with 80-90 species, and Pimelea with 75 species. The 

 family stands between the Myrtiflorso and the Cactales, 

 and also somewhat suggests the Passifloracese. The 

 single perianth, the tubular receptacle, perigynous, defi- 

 nite stamens, the appendages in the tube of the recep- 

 tacle, and the superior 1-celled, 1-ovuled ovary are 

 distinctive. 



Gnidia carinata of South Africa and Daphne Meze- 

 reum (mezereon) of Europe have been used as a purge; 

 as has also the spurge flax (Daphne Gnidium) of 

 South Europe, the caustic juice of which is used in a 

 blistering ointment. A blistering principle is obtained 

 from the bark of Funifera utilis of Brazil; also from 

 Dirca palustris. The roots of Thymelxa tinctoria yield 

 a yellow dye. Paper is made from the cauline fibers of 



