36 DAVENPORT ACADEMY OF NATURAL SCIENCES. 



bracts of L. Chilensis also a double series, only obscured by the close 

 similarity of the separate segments. 



It thus appears that the suggestion of Professor Gray, contained in a 

 notice of Xantus' plants, as early as i860, stating that "the verticillate 

 upper leaves of Lastarricca answer to the involucre, which however 

 encloses a proliferous shoot as well as a flower," contains at least half 

 the truth; also the lately published remark of Mrs. Curran (Bull. Cal. 

 Acad., No. V., p. 2,) that "the enclosing bracts of Lastarricca have as 

 much right to the rank of an involucre as those of Oxytheca, /uteo/a," 

 may, with the explanation now given, be accepted as nearer the truth 

 than the previous theory of the present writer. With the facts thus 

 brought to light by the interesting discoveries of Professor Philippi, the 

 genus Lastarricea, Remy., may be more clearly defined as follows, viz. : 



Lastarri,ea, Remy. — Chorizanthe Lastarritva, Parry, 1. c. 



Involucre triphyllous, united at base, segments unequal, more or less 

 thickened and cuspidate-uncinate, closely sessile in the axil of oppo- 

 site cauline bracts subtending the dichotomous branches and terminal 

 shoots; perianth triangular, coriaceous, 5-6 parted, segments uncinate 

 (resembling the involucre of Chorizanthe) ; stamens 3, inserted on the 

 throat, filaments short, anthers oval; styles short, recurved; akene tri- 

 angular, embryo straight, with linear cotyledons, and short radicle. 



Slender jointed annuals of the Pacific coast of North and South 

 America; differing from Chorizanthe only in its 3-bracteate involucre, 

 and its coriaceous, uncinately awned perianth; nearest to Sect. Acan- 

 thogonum, but differs in its straight embryo. 



Three ? species. 



1. L. Chilensis, Remy. — Chorizanthe Lastarricea, Parry, 1. c. 



Involucral whorls closely adherent, and similar to the external cau- 

 line bracts; perianth sharply triangular, coriaceous, segments unequal, 

 with prolonged uncinate awns. 



Habitat. — Pacific coast of North and South America. 



2. L. stricta, Philippi, ined. 



Involucral whorls distinct from the outer cauline bracts, segments 

 broadly oval, retuse, thick-fleshy corrugated, with a prominent keel 

 terminating in a short recurved cusp; perianth membranaceous, seg- 

 ments nearly equal, spathulate, and shortly uncinate. 



Habitat. — Coquimbo, Chili, S. A. Professor Philippi, 1885. 



3 ?. L. linearis, Philippi, ined. 



Smaller, with more linear bracts; hardly distinct from the last. 



Habitat. — Coquimbo, Chili. Professor Philippi, 1885. 



