258 JUNCACEAE 
rarely flat: inflorescence and flowers as in J. tenuis but darker, sometimes smaller and 
frequently with more rigid parts : seeds oblong, obliquely apiculate, 0.36-0.45 mm. long, 
with about 13 longitudinal ribs, the smooth areolae about as long as broad. 
In dry or sandy soil, Massachusetts to Florida and Texas, mostly near the coast. Spring and 
summer.—When the leaves are expanded and flat this species can be separated from J. tenius by the 
purple base, darker flowers and the semi-cartilaginous auricles. 
15. Juncus setaceus Rostk. Plants in dense tufts. Uppermost sheath usually 
bearing a terete blade similar to the stem, but channeled: other sheaths with minute 
filiform blades less than 1 em. in length: scapes spreading and at length recurved, 4-10 
dm. long: involucral bract appearing like a continuation of the stem, 10-30 em. long: 
inflorescence appearing lateral, 5 cm. long or less: perianth 3-5 mm. long: sepals and 
petals lanceolate, acuminate, rigid, widely divergent in fruit: stamens 6 ; anthers usually 
longer than the filaments : capsules globose-ovoid, shining, mucronate, 1-celled, with in- 
truded placentae, breaking irregularly in age: seeds subglobose, 0.5-0.7 mm. long, retic- 
ulated in about 11 longitudinal rows, the areolae usually a little broader than long. 
In marshes, usually near the coast, Delaware to Missouri, Florida and Texas. Spring and summer. 
16. Juncus répens Michx. Plants stoloniferous. Stems tufted, compressed, com- 
monly 1-2 mm. in width, 5-20 cm. high, or prostrate, often creeping, and sometimes 
attaining a length of more than 5 dm.: leaves with compressed sheaths 2 cm. long or less, 
auriculate ; blades commonly 3-8 em. long and 1-2 mm. broad, filiform-acuminate at the 
apex: heads 1-8, 1 or more often occurring also at the lower nodes, 5-10-flowered : peri- 
anth 6-10 mm. long: sepals subulate-lanceolate, keeled and about 4 shorter than the 
otherwise similar petals: stamens 3, 3—4 the length of the perianth ; filaments several 
times longer than the yellow anthers: capsules subulate, but beakless, about as long as 
the sepals, 3-celled, the valves membranous and breaking away from the placental 
axis in dehiscence : seeds oblong, acute at both ends, 0.3-0.4 mm. long, finely reticulated 
in 25-40 longitudinal rows, the areolae much broader than long. 
In streams and swamps, Delaware to Florida and Texas. Also in Cuba and Lower California. 
Spring and summer. 
17. Juncus filipéndulus Buckl. Plants 1-3 dm. high. Rootstock branching; 
branches hardly longer than broad, congested: stems tufted, 1 mm. broad or Jess: basal 
leaves about 4 the Jength of the stem ; blades 1-2.5 mm. broad : inflorescence consisting 
of 1-5, commonly 2-3, heads each 4-7-flowered : perianth 4-6 mm. long: sepals and 
petals lanceolate, with hyaline margins and green midrib, acuminate into an aristate 
apex, the sepals slightly the shorter: stamens 3, about 3 as long as the perianth ; anthers 
yellow, much shorter than the filaments: capsules about à as long as the perianth, obo- 
void, retuse, mucronate, almost 3-celled : seeds 0.45-0.55 mm. long, oblong, acute at both 
ends, with 14-18 prominent longitudinal costae (and often as many intermediate, much 
less conspicuous ones), the intermediate areas smooth, with an occasional transverse line. 
In low grounds, Tennessee to Arkansas and southern Texas. Spring to fall. 
18. Juncus setósus (Coville) Small. Plants rather loosely tufted, 3-7 dm. high, 
bright green. Stems not much thickened at the base: leaves with auriculate sheaths, 
sometimes quite numerous ; blades 2-5 mm. wide, nearly similar to those of J. margina- 
tus: panicle 3-10 em. high, composed of 20-100 heads, or smaller in depauperate forms : 
perianth 3-3.5 mm. long: sepals lanceolate-acuminate : petals slightly larger than the 
sepals, lanceolate to ovate-lanceolate, setiform-acuminate: stamens 3, much shorter than 
the perianth ; anthers and filaments about equal in length, the former reddish-brown : 
capsules oblong, about as long as the perianth, blunt. [J. marginatus var. setosus Coville.] 
In woods and wet places, Nebraska to Louisiana, Arizona and Mexico. Spring and summer. 
19. Juncus marginatus Rostk. Plants tufted, mostly 1.5-5 dm. high, from branch- 
ing rootstocks. Stems somewhat bulbous at the base: leaves with auriculate sheaths ; 
biades 1-3 mm. broad, 2-4 conspicuous veins in addition to the midrib: panicle 10 cm. 
high or less, composed mostly of 5-10-flowered heads: perianth 2.5-3 mm. long: sepals 
ovate, acute : petals slightly longer, obovate, broadly obtuse, hyaline-margined : stamens 
3, nearly as long as the perianth ; anthers ovoid, reddish brown when dry, much shorter 
than the filaments : capsules equalling the perianth, obovoid, truncate or retuse. 
In meadows or grassy places, Maine to Ontario and Nebraska, south to Florida. -Summer. 
20. Juncus aristulàtus Michx. Plants solitary or sparingly tufted, 6-12 dm. high or 
sometimes lower. Stems markedly bulbous-thickened at the base : leaves similar to those 
described under J. marginatus, but sometimes 5 mm. broad : panicle 15 cm. high or less, 
composed of numerous, usually 20-100 relatively small 2-5-flowered heads: perianth 
about 2.5 mm. long: sepals acute or acuminate : petals oblong or obovate, obtuse, longer 
