CONTRIBUTIONS TO BOTANY. 
9 
round the salient angles of the ovary, by which they become 
more or less hollow or tubular within, their median nervures 
being decurrent along the extreme angles of the ovary. AVhen 
the seed is matured, these lobes, being acute in Boopis, become 
rigid at the point and acicular; in Nastanthus they remain 
rounded, thick, and obtuse ; in Cahjcera and Acicarpha, where 
the lobes are flatter, they greatly enlarge, becoming subulate 
and rigid, and assume the form of very long, sharp, divaricate 
spines, of unequal length ; in Anomocarpus, in the same capitu- 
lum, some of the achsenia become spinescent, as in Calycera, 
while others retain the form of short rigid teeth, as in Boopis, 
both producing in hke manner perfect seeds. In Nastanthiis 
and Anomocarpus, and sometimes in Boopis, the surface of the 
epicarp is reticulated between the nervures with transverse, 
crowded, parallel and almost scalariform venations, the intervals 
often becoming swollen and assuming the appearance of trans- 
verse rugse. 
In Calyceracece the florets are all crowded upon a broad fleshy 
receptacle surrounded by an involucre, the leaflets of which are 
in a single series almost free from one another, in Acicarpha-, 
accreted at the base upon a large fleshy receptacle in Calycera 
and Nastanthus-, and confluent for the greater part of their 
length into a campauulate form in Boopis and Anomocarpus — 
thus remaining free from the receptacle, which is small and 
seated in its centre. In the five last-mentioned genera the re- 
ceptacle is flat or slightly convex ; in Acicarpha it is conical, 
globular, or cylindrical -, in Boopis and Anomocarpus it is small 
and greatly reduced in size. Each capitulum is furnished mth 
numerous crowded flowers ; and in most of the genera, each 
floret is furnished at the point of its origin with a narrow elon- 
gated palea, as in Composites ; but in Anomocarpus the receptacle 
is almost epaleaceous, each floret being inserted in an alveolar 
depression. In Gamocarpha the palese are conjoined in numerous 
circles, from their base half-way up their margins, the upper 
portions remaining free, and these again are united together by 
other palese, thus forming a kind of honeycomb structui’e, with 
deep cells or nests spread all over the receptacle, several florets 
being afiixed to the bottom of each nest. There is some analogy 
in this respect with the structure in Gundelia among Composites, 
where there is a large capitulum, provided with a general invo- 
lucre, which capitulum is composed of a great many tubular 
involucels with a spinosely dentate border, each containing 3-7 
florets ; the greater part of these involucels are agglutinated 
together in a honeycomb-like cylindrical head, and fixed upon 
an elongated central receptacle; these involucels maybe con- 
VOL. II. C 
