NATUEAL ORDERS. 



261 



4:4:4:. LEGUMiNOSiE, the Pea Tribe. — Herbs^ slirubs^ or trees. 

 Leaves alternate, usually compound, stipulate. Sepals 5, more 

 or less united. Petals 5, papilionaceous or regular. Stamens 

 usually perigynous, distinct, or monadelphous, or diadelpliaus ; 

 anthers versatile. Ovary usually a single carpel, 1 or many 

 seeded. Fruit a legume. Seeds exalbuminous ; embryo straight, 

 or with the radicle bent upon the cotyledons. 



a. Characterized by papilionaceous flowers and leguminous fruit ; both, orna- 

 mental and useful. 



Genera. — 1. PAriLioxACE^ — Flowers papilionaceous, the vexillum largest, exte- 

 rior in sestivation. Baptisia, Pickeringia, Lupinus, Crotolaria, Ulex, Spartium, Genista, 

 TrifoUum, Melilotus, Trigonella, Medicago, Indigofera, Psoralea, Amorpha, Dalea, 

 Petalostemon, Glycirrhiza, Galega, Tephrosia, Robinia, Sesbania, Colutea, Astraga- 

 lus, Oxytropis, Phaca, Cicer, Pisum, Ervura, Vicia, Lathy r us, Astrophia, Orobus, 

 Stylosanthes, Arachis, Coronilla, Zornia, ^schynomene, Desmodium, Lespedeza, 

 Hedysarum, Amphicarpa, Vexillaria, Glycine, Ery- 

 thriua, Strophostyles, Galactia, Doliclios, Apios, F'g. 185. 



Lupinaster, Sophora, Phaseolus Thermia. 2. C^s- 

 ALPiN.<E — the vexillum interior — Gymnocladus, Po- 

 maria. Cassia, Tamarindus, Cercis, Gleditschia. 

 3. Mimosa — Flowers regular, valvate in aestivation 

 — Prosopis, Schrankia, Darlingtonia, Acacia. 



Fig. 185, Baptisia ^mc^o?-ia (wild indigo); stem. 

 very branching ; leaves small, bluish-green ; powers 

 small, bright yellow, in loose spikes at the end of 

 the branches. 



445. EosACE^, the Pose Tribe. — 

 Trees^ shrubs., or herbs. Leaves simple 

 or compound, alternate, stipulate. Se- 

 pals 5 (rarely 3 or 4), more or less 

 united, often with as many bracts. Petals as many as the 

 sepals, inserted on the edge of a disk lining the tube of the 

 calyx. Stamens indefinite, distinct, perigynous.. Ovaries soli- 

 tary, or several. Seeds destitute of albumen ; embryo straight. 



a. Properties : fruits important, the bark and root astringent. 



Gexera. — 1. Chrysobalaneve — Petals and stamens more or less irregular ; fruit 

 a drupe ; ovary solitary, cohering with the calyx on one side only ; style arising 

 from the base — Chrysobalanus. 2. Amygdale^ — Ovary solitary, free " from the 

 calyx; style terminal; fruit a drupe — Amygdalus, Prunus Cerasus, Armeniaca. 

 3. RosE^E — Ovaries numerous, free from the calyx ; fruit either follicles or achenia 

 — Rosa, Dalibarda, Rubus, Fragaria, Po- 

 tentilla, Sibbaldia, Agriraonia, Purshia, 

 Geum, Sieversia, Dryas, Spkea, Gillenia, 

 Nuttallia, Tigarea, Stylipus. 4. Pome^ — 

 Ovaries 2-5, cohering witli each other and 

 with the fleshy and pulpy calyx tube ; 

 fruit a pome — Mespilus, Cratffigus, Pyrus, 

 Aronia Sorbus, 5. Sanguisorbe>e — Fruit 

 a nut inclosed in tlie indurated tube of the 

 calyx ; petals none — Sanguisorba, Pote- 

 rium, Alchemilla, Aphanes. 



Fig. 186. a, flower of Rubus strigosus 

 cut vertically ; c, calyx ; pe, petals ; c, sta- 

 mens ; d, the disk lining the base of the 



