16 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM 
fiber, and have numerous other uses. The Manfredas called **amole” 
are one of the commonest soap plants of the country. The root is 
always to be found in great quantities in every Mexican market. 
KEY TO SPECTES, 
Perianth tube strongly curved ......2----.---------- 2-2-2 eee ee eee 1. MW. singuliflora. 
Perianth tube slightly if at all curved, 
Filaments about the length of the tube 
Filaments much longer than the tube, 
Filaments of two lengths .......-.-.-+-----+++---------+-------- 3. M. potosina. 
Filaments of equal lengths. 
cee eee cee eee eee eee eee eeeeees 2. M. maculosa, 
Leaves pubescent ......-22--2220-22-0 22 eee eee eee eee eee eee 4. M. maculata. 
Leaves not pubescent. 
Segments of the perianth much shorter than the tube, 
Leaves spotted .........--22-2--- 2-2-2002 222-222 e ee eee eee 5. M. pringlet. 
Leaves not spotted. 
Margin of leaf armed with “ hooked spines” ....++--+-+-- 6. M. brunnea. 
Margin of leaf entire or nearly so, 
Stamens inserted near the base of the perianth tube ....-- 7. M. virginica. 
Stamens inserted near the top of the perianth tube... 8. M. brachystachys. 
Segments of the perianth equal to or longer than the tube, 
Segments about equal to the tube. 
Leaves spotted .......------------------------+- +--+ 9, M. variegata. 
Leaves not spotted. 
Perianth brownish ......-.---.-----++-220+-2220----- 10. M. elongata. 
Perianth yellow or greenish. 
Flowers in a dense spike ....2..22----2+----++-+---- Ll. M. revolute. 
Flowers in a law spike. ......------+------+++---- 12. M. oltverana, 
Seqments much longer than the tube. 
Leaves spotted ........2----------- 20 e eee eee eee eee eee 13. M. guttata. 
Leares not spotted. 
Leaves short and broad. .....-------------- 000 e eee 14. M. planifolia. 
Leaves narrow and elongated. 
Leaves 3 cm. broad. .....0------- 2-22-2222 22s 15. M. undulata. 
Leaves 1 cin. or less broad. 
Stamens 3 to 4.em, long..-.---- to cee een cee eceeeee 16. M. rubescens. 
Stamens 6 to 7 em. long .-.-.--+--------+----------- 17. M. jaliscana. 
1. Manfreda singulifiora ( Wats.) Rose. 
Bravoa singuliflora Wats. Proc. Am. Acad, 22: 479. 1887. 
Stems slender, 6 to 9 dm. long, glabrous, somewhat glaucous; basal leaves 8 to 10, 
3 dm. long, 4 to 6 mm. wide, acute, with a scarious undulate margin; stem leaves few 
and much reduced above; inflorescence a very lax raceme of 8 to 12 solitary flowers; 
pedicels of flowers 2 to 3 mm. long, of fruit sometimes no longer, sometimes becom- 
ing 15 mm. long; perianth 3 dm. long (including the ovary), more or less curved 
downward, somewhat purplish; lobes spreading, oblong, 6 to 8 mm. long, bearing a 
tuft of hair at apex; filament but shortly exserted; style exserted; carpels globular 
to oblong, about 15 mm. long. 
Type locality: ‘‘ Mountains near Chihuahua.” 
Specimens examined: 
Chihuahua: On cool hillside near Chihuahua City, C. G. Pringle, August 19, 1897 
(no. 1381); in southwest Chihuahua, E,W. Nelson, August 21, 1898 (no. 
4814); near Batopilas, E. A. Goldman, October 4 and 5, 1898 (no. 207); near 
Colonia Garcia, E. H. T. Townsend and E. M. Barber, July 11, 1899 (no. 120), 
