192 SAXIFRAGACE^E. - Saxifraga. 



ORDER XXXIV. SAXIFRAGACE^E. (By A. GRAY.) 



Herbs, shrubs, or sometimes small trees, distinguished from Rosacece by albumi- 

 nous seeds and small embryo ; usually by definite stamens, not more than twice 

 the number of the calyx-lobes ; commonly by the want of stipules ; sometimes by 

 the leaves being opposite ; and in most by the partial or complete union of the 2 to 

 5 carpels (even when free from the calyx) into a compound ovary, with either axile 

 or parietal placentae'. Seeds usually indefinitely numerous. Petals and stamens 

 perigynous. Styles inclined to be distinct. Only the Hydrangiece have numerous 

 stamens. 



A large and polymorphous order, of about 75 genera and five or six hundred species, mainly 

 of the cooler parts of the world, especially in the northern hemisphere. The Pacific and 

 the Atlantic States have about the same number of genera, of which four or five are peculiar 

 to each. 



TRIBE I. SAXIFRAGES. Herbs. Leaves mostly alternate and without distinct stipules. 

 Styles or tips of the carpels distinct and soon divergent. Fruit capsular. 



* Ovary with 2 or rarely more cells and placentae in the axis, or of as many distinct carpels : 



fruit capsular or follicular. 



1. Saxifraga. Stamens 10 (rarely more). Petals 5, dilated. 



2. Boykinia. Stamens 5. Petals 5, dilated, deciduous. Calyx-tube adnate to the ovary. 



3. Bolandra. Stamens 5. Petals 5, filiform-subulate, persistent. Calyx free. 



* * Ovary 1 -celled, with 2 or 3 parietal (or sometimes nearly basal) placentae alternate with the 



styles or stigmas : no sterile filaments. 



4. Tolmiea. Stamens only 3. Calyx long and narrow, gibbous at base. Petals filiform, en- 



tire. Capsule tapering into a stalk-like base. 



5. Tellima. Stamens 10, included. Petals cleft or lobed, rarely entire, conspicuous. Styles 



2 or 3, very short. 



6. Tiarella. Stamens 10 and styles 2 ; both long, filiform and exserted. Petals small, entire, 



in ours inconspicuous and almost filiform. Capsule early and veiy unequally 2-valved 

 to the base. 



7. Mitella. Stamens 10 or in ours 5, v.ery short. Petals pinnatifid or 3-cleft into capillary 



divisions. Styles very short. Capsule depressed. 



8. Heuchera. Stamens 5, and styles 2, both commonly slender. Petals entire, small, some- 



times minute or none. Capsule ovate, 2-beaked, fully half inferior. 



CHRYSOSPLENIUM, if found in California, may be known by the prostrate habit, want of 

 petals, and obcordate compressed capsule. 



* * * Ovary 1 -celled with 3 or 4 parietal placentae directly under as many obtuse sessile stigmas : 



a cluster of united sterile filaments alternate with the stamens. 



9. Parnassia. Calyx 5 -parted. Petals 5, large. Stamens 5. Flower solitary. 



TRIBE II. HYDRANGIE^E. Shrubs. Leaves opposite, simple : no stipules. Fruit capsular. 

 * Stamens 20 or more : seeds numerous. 



10. Fhiladelphus. Calyx-tube adnate to the 4-5-celled ovary. Petals convolute in the bud. 



11. Carpentaria. Calyx nearly free from the 5 -7-celled ovary and capsule. 



* * Stamens fewer : seeds and ovules solitary in the cells. 



12. Whipplea. Calyx nearly free from the 3-5-celled ovary : styles distinct. 



TRIBE III. GROSSULARIE^E. Shrubs. Leaves alternate, simple : stipules adnate to the 

 petiole or wanting. Fruit a berry. 



13. Ribes. Calyx-tube adnate to the 1-celled ovary : placentae 2, parietal, many-seeded. 



1. SAXIFRAGA, Linn. SAXIFRAGE. 



Calyx 5-lobed or parted, free, or its tube more or less coherent with the lower 

 part of the ovary. Petals 5, entire, imbricated in the bud, either withering-persist- 

 ent or deciduous. Stamens 10 (rarely more), inserted with or below the petals on 



