CYPERACEAE 



161 



shorter than the scale, prominently 2-keeled. Lodicules 3. Stamens 3. Styles 2 or 3, 

 somewhat united at the base. Stigmas long, loosely plumose. 



Spikelets borne on radical shoots of the year : stems 4 m. tall or less. 1. A. tecta. 



Spikelets borne on the old stems which are 5 m. tall or more. 2. A. macrosperma . 



1. Amndinaria t6cta (Walt. ) Muhl. Stems 1-4 m. tall, erect, shrubby, branching 

 at the summit : leat'-sheaths smooth or rough, ciliate on the margin ; ligule bristly ; blades 

 lanceolate, 8-20 cm. long, 8-24 mm. wide, flat, more or less pubescent beneath, glabrous 

 above : inflorescence borne on short leafless stems : spikelets 7-10-flowered, 2.5-4 cm. long, 

 on pedicels 2.5 cm. long or less, the first scale sometimes wanting, the flowering scales 1-2 

 cm. long, acute or acuminate, glabrous or pubescent. 



In swamps and moist soil, Maryland to Indiana, Missouri, Florida and Texas. Spring and sum- 

 mer. This and the following species flower only at intervals of several or many years. REED. 



2. Arundinaria macrosperma Michx. Stems woody, 5-9 m. tall, finally branched 

 above : leaf -sheaths ciliate on the margin ; blades lanceolate, 3 dm. long or less, the larger 

 2-3 cm. wide, those on the ultimate divisions smaller and crowded at the summit of the 

 branches : spikelets 3. 5-6 cm. long, on slender more or less leafy branches, the flowering 

 scales glabrous and pubescent, acuminate. 



Along river banks and swamps, forming " cane brakes," Virginia to Florida and Louisiana, and 

 along the Mississippi River and its tributaries as far north as Kentucky, Tennessee and Missouri. Spring 

 and summer. CANE. CANE REED. 



FAMILY 2. CYPERACEAE J. ST. HiL. 1 SEDGE FAMILY. 



Grass-like or rush-like caulescent or scapose herbs, many species perennial 

 by long rootstocks. Stems or scapes (culms) slender, solid or rarely hollow, tri- 

 angular, quadrangular, terete or flattened. Leaves 3-ranked, with closed 

 sheaths : blades narrow. Flowers perfect or imperfect, arranged in spikelets, 

 one (rarely 2) in the axil of each scale (glume, bract), the spikelets solitary or 

 clustered, 1-many-flowered. Scales 2-ranked or spirally imbricated, persistent 

 or deciduous. Perianth hypogynous, composed of bristles, or scale-like parts, 

 rarely calyx -like, or entirely wanting. Androecium of 1-3 stamens, or rarely 

 more. Filaments slender or filiform. Anthers 2-celled. Gynoecium of 2-3 

 united carpels. Ovary 1-celled. Styles or stigmas 2-3, the former often more or 

 less united. Ovule anatropous, erect. Fruit a lenticular, plano-convex, or 

 3-angled achene. Endosperm mealy. Embryo minute. 



Flowers of the spikelets, or at least one of them, perfect. 



Scales of the spikelets enclosing a bractlet or a pair of bractlets. 

 Bractlets 2, convolute around the ovary. 

 Bractlet solitary, minute, posterior. 

 Scales of the spikelets not enclosing bractlets. 



Spikelets perfect or mainly so, rarely of 2 scales and 1 flower, or if polyga- 

 mous, plants with'leaves not densely imbricated on the stems (KyUinga). 

 Scales of the spikelets 2-ranked. 



Perianth present, the members bristle-like. 

 Perianth wanting. 



Spikelets with 2-several perfect flowers : scales several-many. 

 Spikelets with 1 perfect flower : scales 2-4. 

 Scales of the spikelets spirally imbricated all around. 



Base of the style not at all or only slightly thickened, deciduous. 

 Perianth-parts conspicuously elongated. 

 Perianth-parts not conspicuously elongated. 



Scales pubescent : perianth of bristles and dilated scales. 

 Scales glabrous : perianth of bristles only or none. 

 Base of the style manifestly swollen, persistent as a tubercle on the 



achene, or deciduous. 

 Perianth present. 



Spikelets in compound umbels, 1-flowered. 

 Spikelets solitary, several-many-flowered. 

 Perianth wanting. 



Achene not surmounted by a tubercle. 

 Achene surmounted by a tubercle. 



Spikelets in umbels or cymes, without an imbricated involucre. 

 Spikelets in a terminal umbel : base of the style persistent. 

 Spikelets in terminal and axillary compound cymes : most 



of the style persistent. 



Spikelets in heads subtended by an imbricated involucre. 

 Spikelets polygamous, or rarely of 4 scales and only 1 flower. 



Scales of the spikelets 2-ranked. 15. ABILDGAARDIA. 



Scales of the spikelets of spirally imbricated scales. 



Perianth present. 16. SCHOENUS. 



1. LIPOCARPHA. 



2. HEMICARPHA. 



3. DULICHIUM. 



4. CYPERUS. 



5. KYLLINGA. 



6. ERIOPHORUM. 



7. FUIRENA. 



8. SCIRPUS. 



9. WEBSTERIA. 



10. ELEOCHARIS. 



11. FlMBRISTYLIS. 



12. STENOPHYLLUS. 



13. PSILOCARYA. 



14. DlCHROMENA. 



1 Prepared with the assistance of Dr. Nathaniel Lord Britton. 

 11 



