126 



ORDER CXIX. ARACE^E. ORDER CXXV. ORCHIDACEJ3. 



carpel. Ovary, style and stigma wanting. Ovules naked, 1, 2, 

 or more, erect, or sometimes turned downward. Fruit a strobile, 

 or cone, sometimes drupaceous, or a solitary drupaceous seed. 

 Embryo with 2, or frequently more cotyledons. 



A very important family, most abundant in cold regions, and there of the 

 highest use to man, as it includes all the most valuable timber-trees of such 

 countries. The resinous products, such as turpentine, pitch, and resin, are of 

 the greatest importance in navigation, and many of the arts. 



CLASS II. ENDOGENS. 



Stems not distinguishable into regular layers of bark, pith, and 

 wood in the woody species, growing by additions on the inside. 

 Leaves usually parallel-veined, entire, often sheathing at base, 

 rarely attached to the stem by a regular articulation. Parts of 

 the flowers usually in threes or multiples of 3. Seeds with 1 

 cotyledon, rarely with 2 alternate ones. 



GROUP 1. Mostly aquatic and marsh plants. Flowers monoe- 

 cious, dioecious, or perfect. Perianth absent ; or else present, 

 rarely monosepalous, otherwise consisting of 4 or 6 distinct sepals, 

 in 1 series, and the flowers sessile on a spadix, or in dense spikes. 

 Orders CXIX. CXXI. inclusive. _ 



GROUP 2. Leaves parallel-veined, sometimes linear, often 

 fleshy. Perianth of 6, rarely 3 divisions, the segments in 1 or 2 

 series often of different colors. Ovaries 3, or more, partially 

 united ; or else single, adherent to the tube of the perianth, and 

 1 or more than 5-celled. Orders CXXIII. and CXXIV. 



GKOUP 3. Perianth with 6 very irregular segments, and the 

 tube adherent to the twisted ovary. Stamens consolidated with 

 the style in a column, either with granular pollen, or with 2 i 

 pollen-masses attached to the stigmas in pairs. Order CXXV. 



GROUP 4. Leaves parallel-veined. Flowers perfect, not glu- 

 maceous. Perianth of 6 colored segments, more or less adherent 

 to the ovary. Orders CXXVL CXXVIIL inclusive. 



GROUP 5. Leaves reticulately-veined. Segments of the peri- 

 anth 6, often in 2 differently-colored series. Orders CXXIX. 

 CXXXI. inclusive. 



GROUP C. Perianth tubular, colored, 6-parted, or bilabiate ; 

 or else consisting of 6, rarely 4, similarly colored segments. 

 Ovary free from the perianth. Orders CXXXII CXXXV. in- 

 clusive. 



GROUP 7. Perianth segments in 2 series ; the outer glumaee- 

 ous, or herbaceous ; the inner petaloid. Orders CXXXVI. and 

 CXXXVII. 



GROUP 8. Flowers crowded into dense hemispherical heads. 

 Perianth tubular. Order CXXXVIII. 



GROUP 9. Flowers glumaceous, arranged in spikelets, and in- 

 cluded in glumes, or bracts. Ovary 1-celled, 1-seeded. Orders 

 CXXXIX. and CXL. 



GROUP I. 

 ORDER CXIX. Aracese. 



Herbs, or tropical shrubs, with a fleshy rhizoma, or corm. 

 Leaves sheathing at base, simple, or compound, sometimes with 

 more or less reticulated veins. Flowers usually sessile in a ter- 

 minal, or lateral spadix, sometimes monoecious and achlamydeous; 

 sometimes perfect with a perianth of 4 6 sepals. Stamens defi- 

 nite in the perfect flowers, 4 6, usually indefinite in the monoe- 

 cious flowers. Ovary free from the perianth, 1 several-celled. 

 Seeds solitary, or several. Fruit usually a proper berry, some- 

 tunes dry. 



A small and chiefly tropical order, remarkable for acridity, which is espe- 

 cially developed in their roots. This principle is, however, volatile, and can be 

 expelled by heat, and in this way the starchy conns of some species are ren- 

 dered edible. Arum ( Wake Robin), Calla, Symplocarpns (Skunk Cabbage), 

 and tho well-known aromatic Sweet Flag (Acorus), are examples. 



ORDER CXX. Typhaceae. 



Herbs of marshes and ditches. Stems without joints. Leaves 

 ensiform, rigid. Flowers monoecious, arranged in a spadix, which 



is destitute of a spathe, or in globose heads. Perianth of 3 sepals, 

 or none. Stamens 3 6, with long and slender filaments, and 

 cuneiform anthers. Ovary free from the perianth, 1-celled, 1- 

 seeded. Stigmas 1 2. Fruit a utricle. 



A small unimportant order, consisting solely of two genera, Typha (Cat- 

 tail), and Sparganium (Burr-reed). The seed-down of the former is an article 

 of considerable use to upholsterers, in the manufacture of beds and pillows. 



ORDER CXXI. Lemnaceaa. 



Floating plants of a cellular structure. Stems and leaves 

 merged in a frond, from the bottom of which the roots descend, 

 hanging loose in the water. Flowers arising from the margin of 

 the fronds, inclosed, 2 or 3 together, in a membranous spathe. 

 Stamens definite, often monadelphous. Ovary 1-celled, with 1 or 

 more ovules. Stigma 1. Fruit a utricle. 



A small order of minute aquatics, of very simple and humble structure. 

 Lemna (Duck-meat), is our only example. 



ORDER CXXII. Naiadaceas. 



Aquatic plants, with cellular leaves. Flowers inconspicuous, 

 perfect, monoecious, or dioecious. Perianth of 4, distinct sepals, 

 rarely monosepalous. Stamens definite, 4, 2, or 1. Ovaries 1 ; 

 or else 2 4, free from the perianth, distinct. Stigma simple, 

 often sessile. Fruit 1-celled, 1-seeded, indehiscent. 



A very small unimportant order, represented here by Potamogeton (Pond 

 weed), and Zostera ( Wrack-grass), and a few others. 



GROUP II. 

 ORDER CXXIII. Alismacese. 



Marsh herbs, acaulescent. Leaves parallel-veined, but often 

 with reticulated veinlets, sometimes linear and fleshy. Flowers 

 regular, perfect, or monoecious, usually in racemes or panicles. 

 Perianth of 6 sepals, in 2 series. Sepals herbaceous. Petals 

 often colored, sometimes similar to the calyx. Stamens definite, 

 or indefinite. Carpels 3, or more, 1-celled, 1-seeded. Styles and 

 stigmas as many as the carpels. 



A very small order, principally represented by Alisina (Water Plantain), 

 and Sagittaria (Arrow-head). 



ORDER CXXIV. Hydrocharidaceae. 



Aquatic herbs. Flowers dioecious, or polygamous, regular, 

 arising from a spathe, which is often supported on a scape-like 

 peduncle. Perianth with 6 segments, in 2 series, rarely with 3 

 in 1 series ; in the fertile flowers united below in a tube, whicl: 

 is sometimes very long and slender. Stamens definite, or indefi- 

 nite. Ovary 1, or 6 9-celled, adherent to the tube of the peri- 

 anth. Fruit indehiscent. 



Unimportant aquatic plants, of which Vallisneria (Tape-grass), is an ex- 

 ample. 



GROUP III. 



ORDER CXXV. OrchidacesB. 



Perennial, often acaulescent herbs. Leaves simple, entire, 

 parallel-veined, sometimes wanting. Flowers very irregular. 

 Perianth of 6 segments, all usually colored, and assuming various 

 forms, especially the lowest of the 4 inner segments, or lip, which 

 is often spurred. Stamens 3, consolidated with the style into a 

 column, only the central one fertile ; sometimes the two lateral 



