Trichocaulon. | ASCLEPIADE: (Brown). 889 
* Stem-tubercles tipped with a stiff bristle or slender 
spine ; plants 5-24 in, high: 
Corolla with a very prominent raised ring on the 
disk, very dark purple-brown ... Fe ste 
Corolla without a (in 7. piliferum with a very 
slightly) raised ring on the disk : 
¢ Corolla with a distinct cup-shaped or campanulate 
tube containing the corona: 
Stem-tubercles tipped with a rather stiff spine 3-5 
lin. long; corolla yellow vite is ...» (4) Alstoni. 
Stem-tubercles tipped with spine-like bristles 2-3 
lin. long: 
Corolla dark purple-brown ; plants 5-8 in. high : 
Corolla-lobes 2-3 lin, long ; outer corona-lobes 
very spreading, with the divergent teeth 
arranged in pairs behind the inner corona- 
lobes ae ivi (2) piliferum. 
Corolla-lobes 14 lin. long ; outer corona of 5 
erect deeply bifid lobes or pairs of teeth ~ 
alternating with the inner corona-lobes (3) rusticum. 
Corolla yellow : 
Plant 5-18 in. high ; inner corona-lobes about 
half as long as the anthers 
Plant 14-2 ft. high ; inner corona-lobes much 
longer than the anthers, with connivent- 
erect tips ... aS dd iss sie 
tt Corolla without a distinct tube, the united part 
flattish or saucer-shaped ; plants 5-6 in. high : 
Corolla dull yellow, smooth or minutely papillate 
on the inner surface ; outer corona of 5 pairs 
of spreading faleately curved teeth behind the 
inner corona-lobes bas We ies -» (7) flavum. 
Corolla purple-brown on the lobes, yellow around 
the corona, finely puberulous on the inner 
surface; outer corona of 5 erect 3-toothed : 
lobes behind the inner corona-lobes ... -.. (8) officinale. 
** Stem-tubercles short, broad, pointless or tipped with a 
minute point seated in a small depression or ‘‘stem 
smooth, only a little wrinkled” ; plants 2-4 in. 
high : : : 
Corolla without a distinct tube, the united part - 
flattish or saucer-shaped, dark purple-brown ... (9) Marlothii. 
Corolla with a distinct cup-shaped tube containing 
the corona: 
Corolla pale yellow spotted with crimson ; outer ‘ 
- corona 10-toothed, teeth in pairs... ... (10) cactiforme. 
Corolla dark purple-brown; outer corona 15- 
toothed, teeth in 5 groups of 3 aos 2 vom (AL) ee 
(1) annulatum. 
(5) Pillansii. 
(6) grande, 
1. T. annulatum (N. E. Br.); plant 6-18 in. high, branching 
at the base ; stems light glaucous-green, 14-1} in. thick, cylindric, 
with 23-30 vertical series of tubercles tipped with stiff light-brown 
(darker when young) bristles 2}-3 lin. long ; flowers subsessile in 
the grooves between the tubercles ; sepals 1—1} lin. long, subulate- 
acuminate from a broadly ovate base, glabrous; corolla about 
