Part 16 (1/2)

Although these plants reach such a great size, an examination of the stem shows that it is built on much the same plan as that of the other monocotyledons; that is, the steh which run ood idea of this structureacross a corn-stalk, which is built on precisely the same pattern

ORDER IV--_Glumaceae_

The plants of this order rese, narrow leaves with sheathing bases that surround the slender, distinctly jointed stem which frequently has a hard, polished surface The flowers are inconspicuous, borne usually in close spikes, and destitute of a perigone or having this reduced to small scales or hairs The flowers are usually surrounded by lumes, paleae) which are closely set, so as to nearly conceal the flowers The flowers are either hermaphrodite or unisexual

[Illustration: FIG 87--Types of _Glue, _Carex_ (_Cyperaceae_) ?, the lespike of another _Carex_,_E_, a single fruit, 1 _F_, the saed _G_, section of _F_, 3 _em_ the ele spikelet, 2 _J_, a single flower, 3 _K_, a spikelet of flowers of the cole flower, 2 _M_, the base of a leaf, showing the split sheath encircling the ste the embryo (_ees (_Cyperaceae_) and the grasses (_Graular stems, and the sheath at the base of the leaves is not split The co 87, _A_, _G_) and _Cyperus_, of which there are uish There are several co, the e, yellow anthers The female flowers are in similar spikes lower dohere the pollen readily falls upon theenera, _eg_ the bulrushes (_Scirpus_) (Fig 87, _H_), the flowers are hermaphrodite, _ie_ contain both sta 87, _F_) is seed-like, but really includes the wall of the ovary as well, which is grown closely to the enclosed seed The e 87, _G_) Very few of the sedges are of any econoypt, was formerly much valued for its pith, which was rasses, on the contrary, includes thehere They differ enerally, hollow, cylindrical stems, and the sheath of the leaves split down one side; the leaves are in thile those of the sedges are in three

The flowers (Fig 87, _L_) are usually perfect; the stigmas, two in number and like plumes, so that they readily catch the pollen which is blown upon them A few, like the Indian corn, have the flowers unisexual; thethe ”tassel,” and the fe the ear The ”silk” is coes, but the eer and placed at one side of the endosperrasses are comparatively small plants, a few of them are almost tree-like in their proportions, the species of baht of twenty to thirty metres, with stems thirty to forty centimetres in diameter

ORDER V--_Scitamineae_

[Illustration: FIG 88--_Scita plant of Indian shot (_Canna_), le flower,_C_, the single stay_), 1 _D_, section of the ovary, 2 _E_, diagra stamens is indicated by small circles _F_, fruit,_G_, section of an unripe seed

_em_ embryo _p_, perisperm, 2]

The plants of this order are all inhabitants of the warmer parts of the earth, and only a very few occur within the limits of the United States, and these confined to the extree leaves and brilliant flowers, and for this reason are cultivated extensively Various species of _Canna_ (Fig 88) are coe, richly-colored leaves, and clusters of scarlet, orange, or yelloers The leafy sterow rapidly to a height of two er species The leaves, as in all the order, are very large, and have a thickleaves are folded up like a truular in forle stamen is found; or if more are present, they are reduced to petal-like rudi 88, _C_, _an_) has the filament broad and colored like the petals, and the anther attached to one side The pistil (_gy_) is also petal-like There are three circles of leaves for more or less membranaceous, and only the three inner petal-like in texture The ovary (_o_) is inferior, and covered on the outside with little papillae that afterward form short spines on the outside of the fruit (_F_)

The seeds are large, but the embryo is very small A section of a nearly ripe seed shows the e the upper part of the embryo sac which does not nearly fill the seed and contains no endosperm The bulk of the seed is derived from the tissue of the body of the ovule, which in rowth of the embryo sac The cells of this tissue become filled with starch, and serve the same purpose as the endosperm of other seeds

This tissue is called ”perisper to this order, the banana (_Musa_) is much the most important Others of inger (_Zingiber_)

There are three fainger family); and III _Cannaceae_ (_Canna_, _Maranta_)

ORDER VI--_Gynandrae_

By far the greater nu to the orchis family (_Orchideae_), the second fa a small one and unrepresented in the United States The orchids are in sohly specialized of all flowers, and exhibit wonderful variety in the shape and color of the flowers, which are often of extraordinary beauty, and show special contrivances for cross-fertilization that are without parallel a plants

[Illustration: FIG 89--_Gynandrae_ _A_, inflorescence of the showy orchis (_Orchis spectabilis_), 1 (_Orchideae_) _B_, a single floith the upper leaves of the perianth turned back to show the column (_x_) _sp_ the spur attached to the lower petal or lip _o_, the ovary, 1 _C_, the columatic surface, 1 _D_, the two pollen masses attached to a strahich was inserted into the flower, by means of the viscid disc (_d_): i, the masses immediately after their withdrawal; ii, iii, the sae in position _E_, diagra stamens indicated by small circles]

The flowers are always omorphic) The ovary is inferior, and usually twisted so as to turn the flower coone leaves, three in each, and these are usuallyof the ovary) of the inner set This petal, known as the ”lip” or ”labelluer than the others, and different in color, as well as being frequently of peculiar shape In ed backward in a hollow spur (see Fig 89, _B_) In all of the orchids except the lady's-slippers (_Cypripediu 90, _B_), only one perfect stamen is developed, and this is united with the three styles to forynosteregated into two or four waxypolliniuency of insects upon which all but a very few orchids are absolutely dependent for the pollination of the flowers

[Illustration: FIG 90--Forms of _Orchideae_ _A_, putty-root (_Aplectrum_), 1 _B_, yellow lady's-slipper (_Cypripedium_),

_C_, the column of the same, 1 _an_ one of the two perfect stama _D_, _Arethusa_,_E_, section of the columa _F_, the saon_, 1 In the last the ovary is not twisted, so that the lip (_L_) lies on the upper side of the flower]

In the lady-slippers there are two fertile staular shi+eld ter 90, _C_, _st_)

The ovules of the orchids are extremely small, and are only partly developed at the ti very slowly and the ovules h the tissues of the column The ripe seeds are excessively numerous, but so fine as to look like dust

The orchids areht All of our native species, with the exception of a few frorow from fibrous roots or tubers, but many tropical orchids, as is well known, are ”epiphytes”; that is, they grow upon the trunks and branches of trees

One genus, _Vanilla_, is a twining epiphyte; the fruit of this plant furnishes the vanilla of commerce Aside from this plant, the econoh a few of them are used medicinally, but are not specially valuable

Of the five thousand species known, the great majority are inhabitants of the tropics, but nevertheless there are within the United States a nuest and showiest are the lady's-slippers, of which we have six species at the north The most beautiful is the showy lady's-slipper (_Cypripediue, pink and white flowers rival in beauty many of the choicest tropical orchids Many of the _Habenarias_, including the yellow and purple fringed orchids, are strikingly beautiful as are the _Arethuseae_ (_Arethusa_, _Pogonia_, _Calopogon_) The last of these (Fig 90, _H_) differs fro the ovary untwisted so that the labellum lies on the upper side of the flower