GROUPS AND ORDERS OF ENDOGENOUS PLANTS. 237 



CLASS III. ENDOGENOUS or MONOCOTYLEDONOUS PLANTS. 



Stem with no distinction of bark, pith and wood, and without medullary rays or 

 concentric rings ; the woody matter consisting of bundles of fibres and vessels 

 imbedded in cellular tissue, increasing in diameter by the addition of new 

 matter to the centre. Leaves mostly alternate, with no evident articulation, 

 commonly sheathing at the base and entire, generally with parallel veins. 

 Flowers usually with a single perianth, or the calyx and corolla undistinguish- 

 able, the parts arranged in a ternary manner. Ovules enclosed in an ovary, 

 and fertilized through the medium of a stigma. Embryo with a single 

 cotyledon ; or, if two, one is smaller and alternate with the other. 



CO^SPECTUS OF THE GROUPS AND ORDERS. 



Group 1. Flowers mostly on a spadix ; with the perianth simple and scale-like or wanting. — Chiefly herbs. 



Order 106. Arace^. Flowers usually without a perianth, seated on a spadix, which is surrounded by a spatha, or 



sometimes naJied ; the fertile ones commonly below. Ovary 1 - several-celled, with one or more 



ovules. 



107. LemnacejE. Flowers produced from the margin of a frond. Fruit an utricle. — Minute floating plants. 



108. Ttphace*:. Flowers in dense spikes or heads, without a perianth. Stamens numerous, intermixed with 



simple filaments or scales. Ovary with a single suspended ovule. Fruit somewhat drupaceous. — 

 Aquatic or marsh plants, with linear leaves. 



109. Najadace*;. Perianth simple or none. Stamens definite. Ovaries single, or 2 - 4 and distinct, one-seeded. 



Water plants with cellular leaves and sheathing stipules. Flowers inconspicuous, monoecious or 

 perfect. 



Gboop 3. Flowers not on a spadix, furnished with a double perianth (calyx and corolla). Ovaries 3 - 6 or numerous, 

 free, distinct or more or less united. — Aquatic or marsh plants. 



110. ALISM4CE.E. Flowers regular, perfect or polygamous, mostly in racemes or panicles. Sepals and petals 3. 



Seeds usually solitary in each carpel. — Marsh plants, with ribbed leaves and flowers on scapes. 

 Rhizoma usually creeping. 



Obovp 3. Flowers with a single or double perianth, which coheres with the lower part, or with the whole surface of the 

 ovary. — Herbs. 



111. HrDHOCHABiDACEJE. Flowers with regular calyx and corolla, adherent to the ovary. Seeds numerous, — 



Water plants. 



112. Obchidaceje. Flowers perfect, irregular ; the perianth of 6 parts. Ovary inferior ; the single fertile stamen 



(or in Cypripedium the two stamens) coherent with the style. Pollen of 2 or more waxy masses. 

 Ovary inferior, one-celled, with 3 parietal placenta;. Seeds very numerous. — Herbs. 



113. Htpoxide«. Flowers perfect, regular, on scapes. Pcrigonium petaloid, 6-parted, the centre adherent to the 



ovary. Stamens 6. Fruit indehiscent, many-seeded. Embryo straight, in the axis of fleshy al- 

 bumen. — Herbs with grass-like leaves. 



114. IbidacE£. Flowers mostly regular and showy. Perianth G-parted, in 2 series. Anthers eztrorse. Stigmas 



dilated or petaloid. — Herbs, with bulbs, corms or rhizomas. Leaves equitant. 



115. DioscobeacejE. Flower small and dioecious. Perianth 6-parted. Stamens 6. Ovary 3-celled. — Twininjj 



plants ; the leaves ribbed and reticulately veined. 



