Order 67. -THE MADDER WORTS. 



229 



OHnF.K LXA^II. RUBIACE^. The Madderworts. 



Plants witli opposite, sometimes whorled, entire leaves ; the 

 stipules between tlie petioles ; the calyx adherent to the ovary; 

 corolla i-egnlar, inserted on the calyx tube ; 

 lumens inserted on the corolla and as many as its lobes; 

 ovaries 2, united ; with the 2 styles more or less united. 



Analysis of the Genera. 



% Leaves whorled. Herbs with square stems a 



§ Leaves opposite, with small stipules between the petioles.. ..2 



2 Herbs, with the flowers habitually 4-parted 3 



2 Shrubs or trees d 



3 Fb. twin (always in pairs) b 



3 Flowers single (not twin) c 



a Flowers 5-parted. Fruit twin, 



fleshy, berry-like. Madder. Ru^bia. 

 a Flowers 4-parted. Fruit twin, dry, 



separable nuts. Bedstraw. Gallium. 

 b Two fls, on one ovary. Creeping 



stems. Partridge-herry . Mitchel''la. 

 c Carpels 2, 1-seeded, both never open- 

 ing. Fls. axillary, solitary, Dio'dia. 

 c Carp. 2, 1-seeded, one never opening. 



Fls. axillary, clustered. Spermaco''ce. 

 c Carpels 2, few-seeded. Corolla 



much exserted. BlueU. Housto''nia. 

 c Carpels 2, many-seeded. Cor. scarce 

 exserted. Greenhead. Or-DENLAN''DiA. 

 d Flowers 4-parted, in globular 



hds. Button-hush. Cephalan'tuus. 

 d Fls. 5-parted, cymes radiant 



with scarlet sepals. S. Pinckne'ya. 



1. MITCHEL'LA. Partridge-berry. 



Flowers 2 on each double ovary. Ca- 

 lyx 4-parted. Corolla funnel-shaped, 

 hairy within. Stamens 4, short, insert- 

 ed on the corolla. Stigmas 4. Berries 

 composed of the 2 united ovaries, Jn. 



Fig. 497. Mitchella repens, whole 

 plant, witli flowers and fruit a, cross- 

 section of the douMe fruit, showing the 

 two ovaries. 



