XyRT DALES.] 



MAYACE^. 



189 



Order LVII. MAYACE^.— Mayacs. 



Mayacese, Ktinth. Enum. iv. 30 (1843). 



Diagnosis. — Xyridal Fndogens, with 3 sepals alternate with the carpels, 3 petals, 3 stamens, 

 l-celled anthers, parietal placentcB, and a minute embryo on the outside of fleshy 

 albumen. 



Moss-like plants, creeping over clamp places, almost entirely destitute of spiral vessels. 

 Leaves very narrow, pellucid, vmdi\ided. Flowers 0, small, white, pink, or violet. 

 Sepals valvate ? hei'baceous. Petals much longer, 

 imbricated. Stamens 3, inserted into the base of 

 the sepals ; anthers l-celled, adhering by the base 

 to a thread-like filament, openuig at the point only. 

 Carpels 3, alternate with the sepals, combined into 

 a l-celled ovary ; placentee 3, parietal ; ovules 

 sessile, horizontal, orthotropal ; style thread-like ; 

 stigma simple. Capsvde membranous, covered by 

 the peraianent sepals and petals, l-celled, 3-valved ; 

 seeds attached to the middle of the valves, round- 

 ish, ribbed, terminated by a conical tubercle. 

 Albumen shaped like the seed, composed of angu- 

 lar crystal-Uke cells, arranged in a radiant manner. 

 Embryo very minute, antitropal, half plimged in 

 the vertex of the albumen. 



Such appears to be the structure, according to 

 Kunth, and Schott, and EndHcher, of a few plants 

 which are separated from the Spiderworts by the 

 former of these botanists. They are very httle 

 kno\\Ti, and demand a fresh examination, but m 

 the meanwhile appear to be distinguished from the 



Spiderworts by then' peculiar habit, their 1-ceUed Fig. CXXX. 



anthers, and their carpels being opposite the petals 



(according to Schott and Endhcher), while, on the other hand, the XjTids are separated 

 by their monopetalous glumaceous capitate flowers and 2-celled anthers. There is, 

 however, but httle other difference, unless the valvate calyx of the Mayacs and the 

 position of their carpels should afford additional characteristics. This, however, is to be 

 noted, that the figures given by the last mentioned botanists are at variance with their 

 account of the position of the carpels. No spiral vessels were detected by Schleiden in 

 the leaves and stems of Mayaca fluviatilis, except m the flower-stalks. — Wiegm. 

 Arch. V. 231. 



The few species that are described inhabit the marshes of America, from Brazil up 

 to Virginia. 



They are of no known use. 



GENERA. 



Mayaca, Auhl. 

 Biaslia, Vand. 

 Syena, Schreb. 

 Colktia, Flor. Flum. 



Numbers. Gen. 1. Sp. 4. 

 Position. — Coramelynaceae. — Mayace^. — Xyridacese. 



Fig. CXXX.— Mayaca Vandellii; 1. a flower; 2. a cross section of its ovary .; 3. a seed vessel ; 

 two seeds, one of which is cut perpendicularly in order to show the erabrj'o. 



