TAMACEAE . 291 



b. Leaves glaucous ; blades 24-35 mm. broad. 5. H. occidentalis. 



B. Scapes terminated by a single flower : bulbs 1-2.5 cm. in diameter. 



Perianth-tube over 7 cm. long : staminal crown with free tips between 



the filaments. 6. H. Palmeri. 



Perianth-tube less than 5 cm. long : staminal crown truncate between the 



filaments. 7. H. humilis. 



1. Hymenocallis Cayman6nsis Herb. Bulb large, with a short neck : leaf -blades 

 linear-oblong, 3-8 dm. long, 6-8 cm. broad, obtuse, tapering somewhat towards the base : 

 flowers 6-12 together at the top of the scape : perianth-tube 13-15 cm. long ; lobes 10 cm. 

 long: staminal crown funnel-shaped, 2.5 cm. long : ovules 2 in each cavity. 



In sand or sandy soil, Florida and the West Indies. 



2. Hymenocallis Caribaea (L. ) Herb. Bulb subglobose, 7-10 cm. in diameter: 

 leaf -blades linear-oblong, about 4 dm. long, 4.5 cm. broad or more, scarcely tapering either 

 way, acute : scape acutely angled : flowers 6-12 together, terminating the scape : perianth- 

 tube 5-10 cm. long ; lobes 7-9 cm. long : ovules 2 in each cavity. 



In sand or sandy soil, Florida and the West Indies. 



3. Hymenocallis rotatum (Ker.) Herb. Bulb ovoid, 4-5 cm. in diameter, with a 

 prolonged neck and copious stolons : leaf -blades linear, 3-5 dm. long, less than 2.5 cm. 

 broad, bright green : flowers 2-6 together, terminating the scape : perianth-tube 7.5-10 cm. 

 long ; lobes linear, about as long as the tube : staminal crown about 2.5 cm. long, very 

 -rotate : ovules 2 in each cavity. 



In low places or sandy soil, North Carolina to Florida. 



4. Hymenocallis Galvestonensis Baker. Bulb relatively large : leaf-blades linear, 

 4-6 dm. long, 2-2.4 cm. broad : scape 3-4 dm. tall : flowers 4-6 together, terminating 

 the scape : perianth-tube 4-9 cm. long ; lobes 6.5 cm. long. 



In damp places, eastern Texas. 



5. Hymenocallis occidentalis Kunth. Bulbs large : leaf -blades strap-shaped, 

 glaucous, 3-5 dm. long, 2.4-3.5 cm. broad : flowers 3-6, terminating the scape : perianth- 

 tube 6-10 cm. long ; lobes linear, about as long as the tube : staminal crown 25-32 mm. 

 long. 



In moist soil or shaded hillsides, South Carolina to Missouri, Georgia and Mississippi. 



6. Hymenocallis Palmeri S. Wats. Bulb narrowly oblong, 8-24 mm. in diameter : 

 leaf-blades linear, 5dm. long or less, 6-10 mm. wide: scapes 1.5-2.6 dm. tall: flower 

 solitary : perianth-tube 7.5-10 dm. long ; lobes nearly as long as the tube : staminal crown 

 funnel-shaped, 3-4 cm. long, with acuminate tips between the filaments. 



In sand or sandy soil, Florida. 



7. Hymenocallis humilis S. Wats. Bulb about 1.8 cm. in diameter : leaf-blades 

 linear, 10-15 cm. long, about 4 mm. wide : scape shorter than the leaves : flower solitary : 

 perianth-tube about 3 cm. long, dilated at the top ; lobes linear, 5 cm. long : staminate 

 crown broadly funnel-shaped, 16 mm. long, truncate between the filaments. 



In sand or sandy soil, Florida. 



FAMILY 2. TAMACEAE S. F. Gray. YAM FAMILY. 



Perennial herbaceous or somewhat woody vines, with tuberous or knotted 

 rootstocks. Stems twining, unarmed. Leaves often opposite or whorled near 

 the base of the stem, alternate above : blades simple, several-nerved and netted- 

 veined, petioled. Flowers regular, perfect, monoecious or dioecious, in axillary 

 spikes, racemes or panicles. Perianth calyx-like : sepals and petals 3 each, 

 partially united. Androecium of 3-6 stamens at the base of the perianth- 

 lobes. Gynoecium of 3 united carpels. Ovary 3-celled, inferior. Styles as 

 many as cavities in the ovary. Stigmas small. Ovules 1-2 in each cavity. 

 Fruit a 3-winged 3-valved capsule, or berry-like. Embryo small, in the fleshy 

 or almost cartilaginous endosperm. [Dioscoreaceae Lindl.] 



1. DIOSCOREA L. 



Herbaceous twining vines, with fleshy or woody rootstocks. Leaves alternate, at least 

 above : blades often broadest below the middle and cordate : petioles enlarged at the base. 

 Flowers mostly dioecious or monoecious, in spikes, recemes or panicles. Sepals and petals 3 

 each, partially united. Staminate flowers with 3-6 stamens at the base of the limb of the 

 perianth and occasionally with a rudimentary ovary : sepals and petals deciduous. Pistil- 



