338 MONOCOTYLEDONS. 



Class II. MONOCOTYLEDONS. 



Stem not distinguishable into pith, wood, and bark, but, when perennial, 

 consisting of bundles of fibres irregularly imbedded in cellular tissue, with a 

 firmly adherent rind outside. Seeds with one cotyledon, the embryo undi- 

 vided, the young stem being developed from a sheath-like cavity on one side. 



Besides the above characters, Monocotyledons may be generally known by their simple en- 

 tire alternate or radical leaves with simple parallel veins, the base usually encircling or 

 sheathing the stem or the base of the next leaf; and the parts of the flower are most fre- 

 quently in threes, the calyx and corolla, when present, being generally similar in appearance, 

 forming a perianth of six parts. In several families, however, the perianth is wholly want- 

 ing, or the parts reduced in number when irregular, or in the Naiadete in twos or fours ; the 

 leaves are exceptionally pinnately or netted- veined in Scitaminete, in most Aroidea, in Dios- 

 coridea and in Smilax. The stem is woody in the Palms, Screw Pines (Pandanus), and 

 Bamboos. 



* Stem woody. Flowers 6-merous, in a panicle with a spatha. 



CIV. Palm.e. 

 ** Perianth or of small scales. Ovaries and stamens crowded in heads or spikes. 



CV. PandanacejE. Flowers in heads or branched spikes. Anthers stalked. (Stem woody. 

 Leaves long, prickly at the edge.) 



CVI. Aroidea. Flowers on a simple spadix, with a spatha. Anthers sessile. Leaves 

 sheathing at the base, often net- veined. 



*** Ovaries apocarpous. 



CVII. Naiades. Floating plants. Perianth or of 1 to 4 scales. Carpels 1, 2, or 4. 

 CVIII. Alismaceje. Perianth 6-merous. Carpels 3, 6, or more. Aquatic or marsh 

 plants, usually erect. 



**** Ovary inferior. Perianth usually 6-merous in 2 series. 



CIX. HydrocharidEjE. Aquatic plants. Flowers unisexual. Female perianth with a 

 tube, male without. No albumen. 



CX. Scitaminete. Flowers irregular, with 1 to 5 perfect stamina, the remainder of the 

 normal 6 being petal-like and barren or wanting. Seeds albuminous. Leaf-veins usually 

 pinnate. 



CXI. Orchide^e. Flowers irregular. Anthers 1 or rarely 2, sessile on a column bearing 

 the stigma. Embryo homogeneous. 



CXII. Burmanniace^e. Perianth 3- or 6-lobed. Stamens 3 or 6. Ovary 1-celled^ 

 with 3 parietal placentas. Embryo homogeneous. 



CXIII. Iride^e. Perianth of 6 segments, usually petal-like. Stamens 3. Ovary 3-celled. 

 Seeds albuminous. 



CXIV. Amarylude^e. Perianth of 6 segments, usually petal-like. Stamens 6. Ovary 

 3-celled. Seeds albuminous. 



CXV. Dioscoride.e. Flowers unisexual. Ovary 3-celled. Twiners. Seeds albuminous. 



***** Ovary superior, syncarpous. Perianth usually 6-merous, in 2 series. 



CXVI. LiLiACE^E. Perianth regular, wholly petal-like. 



CXVII. Pontederace^e. Perianth usually irregular, wholly petal-like. Aquatic plants. 



CXVIII. CommelynacEjE. Perianth slightly irregular, the inner segments very delicate, 

 the outer more herbaceous. Ovary 3- or 2-celled. Embryo on the edge of the albumen. 



CXIX. Xyridace^e. Perianth irregular, the outer of 1 broad petal-like segment, with or 

 without 2 lateral ones, inner petal-like. Ovary 1-celled, with 3 parietal placentas. 



CXX. JuNCACEiE. Perianth regular, wholly stiff or calyx-like. Flowers hermaphrodite. 



