22 
CONTRIBUTIONS TO BOTANY. 
seven species. Boopis in many points approaches Acicarpha, 
but it differs from that genus in having a gamophyllous invo- 
lucre in the form of a depressed cup with an incised border, 
quite free from its small globular receptacle, which is not of 
larger diameter than its peduneular support, and which remains 
bristled with the persistent radiating palese after the achsenia 
have fallen off : it is also distinguished from that genus by its 
achsenia being quite free from each other, and hot accreted into a 
cylindrical or spherical mass ; and by its calycine lobes, which 
preserve their original form, and do not become enlarged in the 
foiTQ of long excrescent subulate spines. It differs from Caly- 
cera in the union of the free leaflets of the involucre into a 
gamophyllous cup, and in its isomorphous achsenia, not hetero- 
morphous wdth the calycine segments often becoming enlarged 
into extremely long spines. 
The genus Acarpha has been proposed by Dr. Grisebach* 
for a Magellanic plant of this family collected by Lechler. It 
obtained this name on account of the supposed absence of palese 
in the receptacle ; but I have examined authentic specimens of 
Lechlerts collection in the Museum of Paris, and find verj 
distinct palese present in all the capitula, though not accom- 
panying all the florets. Even if this were a distinct genus, 
the name would require to be changed ; but it appears to me 
a true Boopis, as its involucrum shows; and in the peculiar 
form of its achsenia it quite accords with B, multicaulis and 
B. gracilis. 
Boopis, Juss. Char, reformat. — Involucrum gamophyllum, cya- 
thiforme, depressum, submembranaceum, plurinerve, fere ad 
medium 5-10-dentatum, dentibus integris, vel denticulatis, 
lanceolatis, vel 3-angularibus, venoso-reticulatis, rigidulis. 
Receptaculum parvum, convexum, paleolis linearibus, scariosis, 
apice dilatatis, achseniis sequilongis, persistentibus echinatum. 
Flores omnes fertiles et consimiles. Calycis tubus adnatus, 
ovario brevior ; lobi 5, dentiformes, acuti, submembranacei, 
integri vel inciso-denticulati, imo marginibus involutis et cum 
costis prominentibus ovarii accretis. Corolla tubus gracilis, 
ovario longior, superne campanulatus ; limbus 5-fidus, laciniis 
acutis, reflexis. Stamina 5, subexserta ; filamenta brevissima, 
imo in tubulum e contractione tubi corollse ortum connata, 
superne discreta; anthera ad basin connatse, apice liberse. 
Ovarium acute 5-costatum, tubo calycino adnatum, apice libe- 
rum, hinc conicum, 5-sulcatum. Stylus capillaceus, exsertus, 
apice cylindraceo-clavatus. Stigma globulosum, rugosum. 
* Diagn. PI. Philippi et Lechler, p. 37 ; Walp. Ann. v. p. 142. 
