EXPLANATION OF THE PLATES. 55 
veloped fruit ; 3, fragment of the bark of the lower part of the plant, with several large bunches 
of spines. 
Fie. 4-5. Opuntia procumpens, E. & B.: 4, part of a joint; 5, larger bunch of spines from 
another specimen. 
Pu. VII, Fig. 1-2. Opuntia occipentauis, E. & B.: 1, joint of the usual shape and size; 
2, fruit. 
Fie. 3-4. Opuntia aneustata, E. & B.: 3, a large and less spinous joint with a sterile 
degenerate spinous fruit; 4, a smaller, more spinous joint with a full grown ripe fruit. 
Pu. VIII, Fig. 1. Opuntia ENGELMANNI, var. cycLopes, E. & B.: with ripe fruit. 
Fie. 2-3. Opuntia TortTisprna, E. & B.: 2, fragment of a joint with fewer spines and ripe 
fruit; 3, part of a more spiny joint. 
Pu. IX, Fig. 1-5. Opuntia camancuica, E. & B.: 1, a joint with shorter and lighter colored 
spines ig? a joint with larger and darker spines; 3, fragment of a joint with more numerous 
and Gxewded spines ; 4 and 5, ripe fruit of the smaller and largest size. 
Fie. 6-8, Opuntia Mosavensis, E. & B.: 6, a younger bunch of spines’ 7, another from the 
oldest part of the plant; 8, a sterile and degenerate fruit. 
L. X. Fig. 1-2. Opuntra vunearis, Mill.: 1, a young joint with leaves, the older one has 
a single spine and bears/a flower bud; 2, a single leaf magnified 4 diameters. The figures 
of this species have been introduced to exhibit the diagnostic characters and its difference from 
the next species. 
Fie, 3-5. Opuntia Rarrvesquit, E.; 3, an older joint with a flower and a bud, and a younger 
half-grown joint with leaves. This represents the spinous form common in Illinois, Missouri, 
and Arkansas. 4, an older joint of the variety with few spines, bearing numerous fruits of 
different shapes, as they often occur in the same plant; 5, two leaves of different sizes mng- 
nified 4 diameters. ,w 
L. XI, Fig. 1, Opuntia RaFrvesqui, var. Minor, E.: the larger joint spineless, the upper 
one spiny on the margin. 
Fie. 2-3. OprIntiA RAFINESQUII, var. GRANDIFLORA, E.: 2, a joint with flower ; 3, fruit. 
Fie. 4. Opuntia Fuscoatra, E.: a joint with a young fruit just after flowering, fragment of 
an older, very bristly, joint visible. 
Pu I. Fig, 1-3. Opuntra cymocu E. & B.: 1, a joint; 2, a single bunch of spines; 
3, ripe fruit. 
Fie. 4-6. Opuntia stenocuita, E. & B.: 4, a joint ; 5 and 6, a smaller and large fruit. 
Fie. 7-8. Opuntia FustFormis, E. & B.: 7, a joint; 8, a fruit. ‘ 
Fie. 9. Opuntia BRacayaRTHRA, E. & B.: a whole plant with two withered flowers. 
Pu, XII. Fig. 1-5. Opunrra pastnaris, E. & B.: 1, a joint somewhat shrivelled as it appears 
in winter ; a late young joint near its base appears more plump and fresh ; 2, flower ; 3, style; 
4, undeveloped sterile fruit; 5, a whole plant reduced in size to show the singular manner of 
growth. 
Fie, 6-7. Opuntia spHmRocaRPA, E. & B.: joint and fruit. 
Fie. 8-11. Opuntia ERnacea, E. & B.: 8, joint of the usual shape, (only partly finished a 
9 and 10, bunches of spines ; 11, fruit. 
Pr. XIV. Fig. 1-3. Opuntia Missourrensts, var. ruFisPiIn®§ E. & B.: 1, a joint, (only partly 
completed ;) 2, a very full bunch of spines; 3, fruit. 
Fr UNTIA MIsSOURIENSIS, var. PLATYCARPA, E.: fruit. 
Fra. 5-7. Opuntia MIssourrensis, var. MIcRosPERMA, E.: 5, joint (unfinished) with flower; 6, 
bunch of spines ; 7, fruit. 
Fig. 8-10. Opuntia Muissovrrensis, var, apisprna, E. & B.: 8, joint (unfinished); 9, bunch 
of spines ; 10, fruit. 
Pu. XV, Fig. 1-4. Opuntra Missovrreysts, var. rricHopHora, E. & B.: 1, part of an old stem 
