1810 TILLAGE 



not merely a means by which seeds can be put into the 

 land, weeds killed, and the crop taken out. 



Tillage improves land in many ways. It divides and 

 pulverizes the soil, gives the roots a wider "pasturage," 

 as Tull puts it, increases the depth of the soil, and im- 

 proves its physical condition with respect to warmth 

 and dryness. 



Tillage also saves moisture by deepening the arable 

 soil so that moisture is held, and also by checking 

 evaporation from the surface by means of a thin blanket 

 or mulch of pulverized earth that is made by surface- 

 working tools. Water is lost from the soil by under- 

 drainage and by evaporation from the surface. The 

 more finely the soil is pulverized, within certain limits, 

 the more water it will hold. Its capillary power is in- 

 creased. As the water evaporates from the surface, the 

 moisture is drawn up from the under surface so that 

 there is a more or less constant flow into the atmos- 

 phere. If any foreign body, as a board or a blanket, is 

 spread on the land, the evaporation is checked. A 

 similar result follows when the soil is covered with a 

 layer of dry ashes or sand or sawdust. Very similar 



2515. Cryptanthus zonatus, commonly known as 

 Tillandsia zebrina (X %) 



results are also secured when the surface is made fine 

 and loose by means of frequent shallow tillage. The 

 capillary connection between the surface soil and the 

 under soil is thereby broken. This surface soil itself 

 may be very dry, but it serves as a blanket or mulch to 

 the soil beneath and thereby keeps the under soil moist. 

 In many instances this conservation of moisture by fre- 

 quent shallow tillage is the chief advantage of the til- 

 lage of the land during the growing season. 



Land that is well tilled has different chemical rela- 

 tions from that which is neglected. Nitrification, de- 

 composition and other chemical activities are hastened. 

 The stores of plant-food are rendered available. The 

 soil is made more productive. 



The first requisite for the growing of the plant is to 

 have the soil in such condition that the plant can thrive 

 in it. It is only when the land is well tilled and pre- 

 pared, or when its physical condition is nearly or quite 

 perfect, that the addition of concentrated fertilizers may 

 be expected to produce the best results. The fertilizing 

 of the land, therefore, is a secondary matter; tillage is 

 primary. 



The ideal tillage of the land is that which is prac- 

 ticed by the gardener when he grows plants in pots. 

 The soil is ordinarily sifted or riddled so that unneces- 



TILLANDSIA 



sary parts are removed, and mo^t of it is brought into 

 such condition that the plants can utilize it. The gar- 

 dener adds leaf-mold or sand or other material, until 

 the soil is brought into the proper physical condition. 

 He also provides drainage in the bottom of his pots or 

 boxes. Often the gardener will produce as much from 

 a handful of soil as a farmer will produce from a bushel. 



L. H. B. 



TILLANDSIA (Elias Tillands was professor of medi- 

 cine at the University of Abo, Sweden; in 1073 made a 

 catalogue of plants of the vicinity of Abo) . Uromeliaceoe. 

 Tillandsiais are mostly epiphytes and all natives of 

 America. They are allied to billbergias, aschmeas, 

 guzmanias, pineapples, and the like. Many species are 

 described in horticultural literature as having been in- 

 troduced into cultivation, but most of these are known 

 only to amateurs and in collections where species of 

 botanical interest are chiefly grown. In the American 

 trade about 30 names occur, many of which are to be 

 referred to other genera. The generic limits of Til- 

 landsia, as of most bromeliaceous genera, are ill defined. 

 By different authors a given species may be placed in 

 any one of a half dozen genera. Lately, Tillandsia and 

 Vriesia have been merged, but in this book Vriesia is 

 kept distinct, following Mez's monograph. It is useless 

 to attempt a description of all the Tillandsias that by 

 chance may occur in collections. Persons who want to 

 know the species other than those regularly in the trade 

 should consult Baker's "Handbook of the Bromeliacese," 

 ,1889, or Mez's "Bromeliaceffi" in DeCandolle's "Mono- 

 graphise Phanerogamarum," 1896. The latter work, 

 which regards Vriesia as a separate genus, admits 248 

 species of Tillandsia. Some of these species extend 

 northward into the United States, growing chiefly in 

 Florida, although one or two reach southern Georgia, 

 and the Spanish moss (which is Tillandsia usneoides) 

 reaches Virginia and is common throughout the South. 

 The native upright Tillandsias are not in the general 

 trade, but they are offered by one dealer in southern 

 Florida: of such are T. recurvata, T. tenuifolia, T. 

 fasciculata, T. utriculata. 



Tillandsias are usually known as "air-plants" to gar- 

 deners. They are perennial herbs, mostly of upright 

 growth (the common T. usneoides being a marked ex- 

 ception), the bases of the narrow entire leaves often 

 dilated and forming cups that hold water and in which 

 utricularias and other water plants sometimes grow. 

 The flowers are usually borne in spikes or heads, singly 

 beneath bracts; they are perfect, with 3 sepals and 

 3 petals which are twisted or rolled in the bud, 6 

 stamens, a superior ovary with filiform style: fr. a 

 3-valved capsule, containing hairy or plumose seeds. 

 Vriesia is distinguished by having one or two scales or 

 ligules at the base of the petals on the inside, whereas 

 the petals of Tillandsia are eligulate; however, there 

 are intermediate forms and it is sometimes a matter of 

 individual opinion as to which genus shall receive a 

 given species. Some of the cultivated Tillandsias be- 

 long to still other genera. This is the case with T. 

 zebrina, which is properly Cryptanthus zonatus (Fig. 

 2515). This is an odd plant, producing crinkled deflexed 

 saw-edged leaves, which are whitish beneath and 

 brown-barred above, and small clusters of white flowers. 

 See p. 404, where other kinds of Cryptanthus in the 

 American trade are described. 



Tillandsias are grown both for foliage and for flowers. 

 The foliage is usually scurfy and sometimes blotched. 

 Many of the species are very showy when in bloom, 

 sending up strong central clusters of blue, violet, red, 

 yellow or white flowers. In nature, the seeds are 

 carried in the wind by means of the soft hairs, and find 

 lodgment on trees, where the plants grow. A few 

 species, however, grow on the ground. In cultivation, 

 most of the species are treated as pot-plants. The 

 growing season is summer. In winter the plants should 

 be kept nearly dormant, although not completely dry. 

 They need a warm temperature and plenty of light 

 while growing. Give a soil rich in peat. In some 

 cases sphagnum may be added to advantage. Prop, by 

 suckers; also by seeds. For further cultural notes, con- 

 sult Billbergia. Other bromeliaceous genera described 

 in this book are Bromelia, yEchmea, Karatas, Cryp- 

 tanthus, Ananas, Pitcairnia, Puya, Guzmania. 



