The genera of South African plants : arranged according to the natural system / by William Henry Harvey.

  • William H. Harvey
Date:
1868
Catalogue details

Licence: Public Domain Mark

Credit: The genera of South African plants : arranged according to the natural system / by William Henry Harvey. Source: Wellcome Collection.

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    resemble eacb other more than they do any other species; the species so brought together are collectively called a Genus, and the common name is the generic name. Each species is further distinguished from the others of the same genus by the addition of an adjective epithet, or specific name. Every sj>ecies has thus a botanical name of two words. In Latin, the language usually used for the pm-pose, the first word is a substantive usually of Greek oi-igin and Latinized, iind designates the genus; the second, usually a Latin adjective, indicates the species. 180. The genera thus formed being very numerous, they have been grouped together on similai’ principles—associating those which resemble each other most nearly—into Families or Natural Orders, to each of which a name has been given. This is, however, for the purpose of study or comparison. In speaking of a species it is only necessary to give the generic and specific names. The name of a Natural Order or Ftunily, in Latin, is im adjective plural, usually formed from the name of some ono typical genus, generally the best known, the first discovered, or the most marked. Thus Itammculacca; is the Order of which the Jiantaicnlus is tho ty])ical genus; Gcraniaccee the Order of tho Geranium and its allies, etc. 181. The number of species included in a genus, or tho number of genera in an Order, is very unequal. Some genera contain but ono, others but two or llireo species; in others, several hundred species aro associated together. There is a simihir discrepancy in the number of genera in tho several Orders. 182. Orders aro collected into Classes; and whore Orders contain a largo number of genera, or genera a large nimibor of species, a further subdivision is ro(iuircd. Tho names of tho several groups most generally adojjted are as follows, beginning with tho most comprehensive or highest divisions:— Classes : Genera: Subclasses or Alliances. Natural Orders : Suborders. Tribes. Subtribes. Divisions. Subdivisions. Subgcncra. Sections. Subsections. Species: Varieties. 183. Classes, Orders, Genera, and their subdivisions, aro called natural, when, in forming them, all resemblances and diff'eroncos aro taken into account, valuing them according to their importance; artificial, when resemblances and diflerences in some ono, or very few particulai-s only, aro tiilcen into account. IV. Collection, Presehvation, and Examination of Plants. 184. Though ])l(tnts can bo most easily and satisfactoiily examined when freshly gathered, yet as time will rarely admit of this being done, and as it is also desirable to compare with other plants previously observed or collected, specimens must bo selected for leisurely observation at home, and for prcsom'ation for future reference. 185. A botanical Specimen should bo, as much as possible, an epitome of the species which it represents, and if the species bo variable, several specimens are necessary. To bo perfect, it should have root, stem, leaves, fiowers (both open and in bud), and fruit (both young and mature). It is not always, however, possible to gather such complete specimens; but tho