230 



SAXIFRAGACEAE. 



VOL. II. 



i. Chrysosplenium americanum Schwein. Golden 

 Saxifrage. Water Carpet. Fig. 2185. 



Chrysosplenium oppositifollum Walt. Fl. Car. 140. 1788. Not L. 

 C. americanum Schwein.; Hook. FL Bor. Am. i: 242. 1832. 



Stems slender, decumbent, forked above, glabrous or very 

 nearly so, 3'-8' long. Lower leaves opposite, the upper often 

 alternate, broadly ovate, orbicular or somewhat reniform, ob- 

 tuse or truncate at the base, rounded at the apex, crenate or 

 obscurely lobed, 2"-io" wide ; flowers sessile, axillary, usu- 

 ally solitary, about i" broad; calyx-lobes commonly 4, yel- 

 lowish, or purplish within; stamens commonly 8; anthers 

 orange-red. 



In wet, shaded places, Nova Scotia to the Saskatchewan region, 

 south, along the mountains to Georgia, and to Ohio, Michigan and 

 Minnesota. March-June. 



2. Chrysosplenium iowense Rydb. Iowa Golden Saxi- 

 frage. Fig. 2186. 



Chrysosplenium ioivense Rydb.; Britton, Man. 483. 1901. 



Flowering stems erect, glabrous or pubescent, 2'-6' high, 

 branched above. Leaves all alternate, the basal ones long- 

 petioled, reniform, or cordate, often pubescent on the upper sur- 

 face, 3"- 1 8" wide, or crenate with 5-11 rather broad lobes ; 

 flowers mainly terminal, corymbose; calyx-lobes commonly 4, 

 orange-yellow within; stamens usually 8. 



On wet mossy slope, Decorah, Iowa. May-June. Confused with 

 Chrysosplenium alternifolium of Europe, in our first edition. 



Family 48. HYDRANGEACEAE Dumort. Anal. Fam. 36, 38. 1829. 



HYDRANGEA FAMILY. 



Shrubs or trees or vines with simple opposite leaves and no stipules. Flowers 

 perfect or the exterior ones of the clusters sterile and conspicuous. Petals and 

 sepals generally 5. Stamens twice as many as the sepals, or numerous, epigynous. 

 Carpels 2-10, wholly united or the apex free, the lower half at least enclosed by 

 and adnate to the calyx. Seeds numerous ; endosperm generally copious ; embryo 

 small. 



About 1 6 genera and 80 species, of temperate and tropical regions. 



Sepals and petals 5 or fewer ; shrubs. 



Petals valvate ; stamens 8 or 10 ; corolla small. 



Petals convolute ; stamens 15-60 ; corolla large. 

 Sepals and petals 7 or more ; woody vine. 



1. Hydrangea. 



2. Philadelphus. 



3. Decumaria. 



i. HYDRANGEA [Gronov.] L. Sp. PI. 397. 1753. 



Shrubs, or some Asiatic species small trees, with opposite simple petioled leaves and ter- 

 minal corymbose flowers. Stipules none. Exterior flowers of the corymb often apetalous, 

 slender-pedicelled, sterile, but with enlarged and very conspicuous calyx-lobes, or sometimes 

 the whole corymb changed to these sterile flowers ; fertile flowers small. Calyx-tube (hy- 

 panthium) hemispheric or obconic, adnate to the ovary, 4~5-lobed. Petals 4 or 5, valvate. 

 Stamens 8 or 10, inserted on the disk. Filaments filiform. Ovary 2-4-celled; styles 2-4, 

 distinct, or united at the base; ovules o. Capsule membranous, usually 2-celled, ribbed, 

 many-seeded, dehiscent at the bases of the styles. [Greek, water-vessel, from the shape of 

 the capsule.] 



About 35 species, natives of eastern North America, eastern Asia and the Himalayas, and South 

 America. Besides the following, 2 or 3 others occur in the southeastern States. Type species : 

 Hydrangea arborescens L. 



Leaves glabrous or somewhat pubescent beneath. i. H. arborescen-s. 



Leaves tomentose beneath. 2. H. cinerea. 



