132 



The Thatch Palms 



fruit is usually a drupe, or sometimes berry-like with a hard usually homy endo- 

 sperm, often hollow and rarely channeled; embryo near the surface. 



In addition to the following arborescent genera, RhapidophyUum is repre- 

 sented in our area by the shrubby R. Hystrix (Fraser) H. Wendland, the Blue 

 palmetto, or Needle palm of the southeastern states. 



Leaves nearly orbicular, palmately cleft. 



Calyx and corolla united into a 6-lobed or truncate perianth. 



Endosperm of seed smooth; fruit white or nearly white when ripe 

 Endosperm channeled; fruit black when ripe. 

 Calyx and corolla distinct, not united. 

 Petioles unarmed. 

 Petioles armed. 



Filaments separate, slender; Californian. 

 Filaments triangular, united into a cup; Floridian. 



Seed oblong; low palm usually with underground stem. 

 Seed depressed-globose; slender erect palm. 

 Leaves longer than wide, pinnately parted. 



Endosperm of seed not enclosing a watery fluid; stamens exserted. 

 Fruit oblong, sessile. 

 Fruit 2-lobed or 3-lobed, stalked. 

 Endosperm bony, hollow, enclosing a watery fluid; stamens included. 



1. Thrinax. 



2. Coccothrinax. 



3. Sabal. 



4. Neowashingtonia. 



5. Serenoa. 



6. Paurotis. 



7. Roystonca. 



8. Psendo phoenix. 



9. Cocos. 



I. THE THATCH PALMS 



GENUS THRINAX SWARTZ 



IX or 8 species of Thatch palms are known, natives of Florida, the 

 West Indies, and Central America. They have slender trunks and 

 round, palmately cleft leaves, with smooth stalks, the leaf- segments 

 2-cleft, the hgule at the base of the leaf-blade hard, short, usually 

 pointed, the base of the leaf-stalk expanded into a broad, fibrous sheath. 



The flowers are in stalked, drooping, or spreading panicles, subtended by 

 several leathery, tube-hke spathes, and are vety numerous, small, perfect, and 

 either distinctly stalked or nearly sessile; the calyx and corolla are united into a 

 6-lobed perianth; the 6 stamens are borne on the base of the perianth and have 

 either subulate or nearly triangular filaments; the i -celled ovary tapers into a 

 rather slender style, tipped by a flat or concave stigma, which is oblique in some 

 species. The fmits are small globose drupes, white or greenish white when ripe, 

 the thin flesh enclosing the hard smooth brown seed. 



Thrinax (name from the Greek) has as its type species, Thrinax parviflora 

 Swartz, of Jamaica; two species inhabit southern Florida. 



Flowers nearly sessile; filaments triangular, united below. 



Flowers distinctly stalked; filaments subulate, scarcely united below. 



1. T. microcarpa. 



2. T. floridana. 



