CHORIZANTHE. 47 



the extremity. In succeeding allied species this special character gives 

 place to a simple protuberance at the base of the involucre (C mem- 

 branaced). In sustaining the view adopted by Mr. Watson of including 

 Cenirostegia, Gray, in Chorizanthe, making it a section merely, it was 

 satisfactory to find that an undoubted Chorizanthe species, viz., C. Spi- 

 nosa, Watson, has quite constantly more than one flower, sometimes 

 two fully developed, but generally the secondary more or less imperfect. 

 It was a still greater surprise that a suspicion floating in my mind, that 

 C. membranacea should come into closer relations to section Ceniro- 

 stegia, was confirmed by discovering, on close examination, evident 

 traces of a second undeveloped flower, thus bringing this otherwise 

 anomalous species clearly into this section. 



The gradation to single flowers, in the Acafithogonum section, com- 

 bined with other characters, satisfactorily rounds out what I have des- 

 ignated as group A. Campylosperma, including all the species with in- 

 flexed radicle, and orbicular accumbent cotyledons. 



In passing to the second main division of group B. Orthosperma, 

 with oval or linear cotyledons and straight radicle, there is a very nat- 

 ural transition afforded through the section Chorizanthella and Mu- 

 cronea to Euchorizanthe. This will be apparent to any one who will 

 place the species in the order indicated in the following synoptical 

 arrangement, which carries the species down by regular steps to the 

 most simple or reduced form. 



It was mainly from a consideration of the uniformity and persistence 

 of the involucral characters that I was induced carefully to examine 

 the anomalous genus Lastarricea, Remy. This is described by authors 

 as without an involucre, assuming that what clearly takes the position 

 and has all the external characters of an involucre to be a proper 

 perianth. Now, as the obvious use of the involucre in this natural 

 order of plants is the protection of the essential reproductive organs, 

 when the object, as in this case, is fully accomplished, the less essen- 

 tial internal covering, represented by the perianth, can be most safely 

 dispensed with. Therefore, recognizing in Lastarr'uea such an external 

 envelope, corresponding in every way to what in all the aUied species 

 of Chorizanthe is regarded as an involucre, in failing to find the ordinary 

 perianth within, the reasonable supposition is that, being needless, it 

 has become obsolete. Or, if a different view should be preferred, lead- 

 ing to the same result, the perianth, instead of being merely sessile, has 

 become adnate to the tube of the involucre. To confirm either of 

 these views, the insertion of the reduced stamens is plainly indicated 



