170 SAXIFRAGACEAE. 



Ovary with 2, rarely more, cells. 



Stamens 5. 1. Therofon. 



Stamens 10. 2. Saxifraga. 

 Ovary 1 -celled. 



Stamens 5. 3. Heuchera. 



Stamens 10. 4. Lithophragma. 



1. THEROFON Raf. 



Perennial herbs with creeping rootstocks and leafy 

 stems. Leaves alternate, round-reniform, palmately 

 lobed and incised or toothed with callous glandular tips; 

 petiole mostly with a stipular dilation at base. Flowers 

 white, paniculate or in corymbose cymes. Calyx 5-lobed, 

 the tube adherent to the ovary, at length globular or 

 ovate. Petals 5, entire. Stamens short, alternating 

 with the petals; anthers 2-celled. Ovary 2-celled. 

 Fruit a capsule, dehiscent down the styliferous beaks. 

 Seeds ovoid, minutely papillose. 



1. T. elatum (Nutt.) Greene. Slender, 3-6 dm. high, glabrous 

 or somewhat glandular-pubescent, the dilated bases of the petioles 

 with brown bristly hairs, otherwise smooth or nearly so; leaves 

 thin membranous, 5-7 cm. broad, deeply 5-7-lobed; calyx-lobes 

 lanceolate-triangular, often slightly toothed above; tube oval, 

 urceolate in fruit; petals cuneate-elliptic, obtuse, 3.5 mm. long, much 

 exceeding the calyx-lobes; claw very short. {Boykinia occidentalis 

 T. & G.) 



Topango Canyon, Davidson. 



2. T. rotundifolium (Parry) Wheelock. Stem villous-pubescent 

 and glandular, 4-8 dm. high, leafy; leaves 5-10 cm. broad, crenately 

 incised and toothed, thin, nearly glabrous above, petioles densely 

 villous, the slightly dilated base with brown bristly hairs; peduncles 

 axillary and terminal; flowers short-pedicelled, secund on the few 

 elongated branches; calyx campanulate, becoming broadly urceolate 

 in fruit, its lobes entire, acute; petals 2-2.5 mm, long, scarcely 

 exceeding the calyx-lobes, spatulate; the claw twice as long as the 

 rounded blade. {Boykinia rotundifolia Parry.) 



Frequent in canyons in the San Gabriel Alountains, 2500-4500 

 feet altitude. May-July. 



2. SAXIFRAGA L. Saxifrage. 



Stemless or short-stemmed herbs with alternate or 

 mostly basal leaves and corymbose, paniculate or rarely 

 solitary small flowers. Calyx 5-lobed or 5-parted, its 

 tube free or adnate to the base of the ovary. Petals 5, 

 equal, entire. Stamens 10, inserted with the petals; fila- 

 ments filiform; anthers 2-celled. Carpels 2 or rarely 3, 

 distinct or more or less united into a 2-celled ovary; 



