Xyridales.J 



XYRIDACEiE. 



^W| 



Order LV. XYRIDACE^.— Xyrids. 



Xyrideae, Kunth inHumb.N. G.et Sp. 1. 255. (1815) a sect, o/ Restiaceae ; Agardh Aphorism, 158. 

 (1823) ; Desvaux in Ann. des Sc. 13. 49. (1828) ; Endl. Gen. xlvii. ; Mexsner,p. 407 ; Kunth Enum. 

 4. p. 1.— Rapateae, Endl. I. c 



Diagnosis. — Xyridal Endogens, with 3 sepals opposite the carpels, 3 petals, 3 fertile sta- 

 mens, parietal placeiitce, and a minute embryo on the outside of fleshy albumen. 



Herbaceous sedgy plants with fibrous roots. Leaves radical, ensiform, or filiform, 

 with enlarged scarious sheathing bases. Flowers in terminal, imbricated, scaly heads. 

 Sepals 3, glumaceous. Petals 3, 

 thin, long, and coloui'ed, united 

 into a monopetalous corolla. Fer- 

 tile stamens 3, inserted upon the 

 claws of the petals ; anthers 

 turned outwards, 2-celled ; ste- 

 rile stamens alternate with the 

 petals. Ovary single, 1 -celled, 

 \\'ith parietal placentae ; ovules 

 numerous, orthotropal ; style 

 trifid ; stigmas obtuse, multifid, 

 or undivided. Capsule 1 -celled, 

 3-valved, many-seeded, with pa- 

 rietal placentae. Seed \v\t\\ the 

 embryo on the outside of the 

 fleshy albumen, and at the end 

 most remote from the hilum. 



These plants join to the habit 

 of Sedges and other glumaceous plants, the floral character of Spider- 

 worts ; and this circvmistance alone would lead to the suspicion that 

 they form a peculiar natural Order. They are brought into contact 

 with the Aphyllanth Lilies by means of the genus Borya, which is 

 so intermediate between the Orders that it is hard to say to which it 

 belongs. The Xyrids were united with Restiacese, by Bro^\ii and 

 others, but separated as a distinct Order by Agardh and Desvaux, 

 and they appear to be essentially distinguished by the higher deve- 

 lopment of their floral envelopes, a character which must be regarded 

 as more important than the mere accordance in the sti-ucture of the 

 seed, in consequence of which chiefly they have been retained in Res- 

 tiaceae. Rapatea and Dasypogon are so imperfectly described that 

 it is impossible to say where they belong : but their habit refers them 

 either here or to the Rushes. 



All are natives of the hotter parts of the world, chiefly in the tro- 

 pics of America, Asia, and Africa. Two or three species of Xyi'is 

 are found in the southern states of North America. 



The leaves and root of Xyiis indica are employed against itch and 

 leprosy in India ; X. americana is used for the same purposes in 

 Guiana, and X. vaginata in Brazil. 



t- 



Xyris, Linn. 

 Abolboda, H. eiB. 

 Chloerum, Willd. 



GENERA. 



? Acoridium, Acen. 

 Rapatea, Aubl. 



Mnasium, Schreb. 



Spathanthus, Desv. 



Dasypogon, R. Br, 



Numbers. Gen. 5. Sp. 70. 

 Cyperacece. 

 Position. — Mayaceae. — Xyridace^. — CommeljTiacese. 



Fig. CXXVIII. 



Fig. CXXVIII.— XjTis operculata ; 1. a flower seen in front ; 2. a style, stigmns and .stamens. 



