216 LYVTHRACEX. . AMMANNIA. 
smooth or nearly so: leaves in numerous whorls of 6-8, the filiform or 
linear segments acute, more or less aculeate-dentate. 44 to one inch long: 
achene 2 lines long or more, elliptical, somewhat compressed, shortly stipi- 
tate, with a short spine or tubercle on each side near the base, not mar- 
gined : style aslong as the achenes. Washington to California, the East- 
ern States and Europe. 
OrpeR XXXVI. LYTHRACEA Lindl. Nat. Syst. ed. 2, 184. 
Herbs, rarely shrubs or trees, with usually 4-sided branches 
opposite, rarely a ternate, entire leaves without stipules and 
flowers in the axils or in terminal racemes. Sepals combined 
into a 4 -7-toothed or lobed calyx; the lobes valvate or distant 
in the bud; the sinuses sometimes produced into accessory 
lobes or processes. Petals alternate with the proper lobes of 
the calyx and inserted on its throat, deciduous, sometimes 
wanting. Stamens inserted into the tube of the calyx below 
the petals, equal to them in number, or 2-4 times as many, 
rarely fewer: anthers short, introrse. Ovary enclosed in but 
free from the calyx, 2-4-celled, with numerous ovules in 
each cell; the placentz in the axis: style filiform, sometimes © 
short or almost none: stigma usually capitate Capsule mem- 
branaceous, surrounded by the calyx, often one-celled by the 
obliteration of the partitions, dehiscent either longitudinally or 
irregularly. Seeds numerous and small, rarely few and large, 
anatropous, without.albumen. Cotelydons flat and foliaceous. 
1. Ammannia. Calyx barely 4-angled, short: stamens 4 or 8: capsule 
globular. 
2. Lythrum. Calyx striate, cylindrical: petals usually 6: stamens 
as many or twice as many: capsule oblong or cylindrical. 
AMMANNIA Houst. L. Gen. n. 155. 
Herbs with square stems, opposite entire leaves and axillary 
bracteolate flowers. Calyx more or less campanulate, 4—5-toothed 
or lobed, the sinuses usually expanding into spreading accessory 
teeth or horns, Petals as many as lobes of the calyx or want- 
ing. Stamens as many or twice as many as lobes of the calyx: 
Ovary 2—4-celled: style short or rather long: stigma capitate, cap- 
sule globose or ovoid, included in the calyx, either bursting trans- 
versely or opening by valves. Seeds numerous, attached to thick 
central placente. et: 
A. latifolia L.Sp.115. Stems erect, branching, 6-24 inches high: 
leaves linear-lanceolate, acute, dilated and obtusely cordate-auriculate at 
base, closely sessile, 2-3 inches long: flowers 1-5 in each axil, somewhat 
pedunculate, at least when solitary: calyx 4-angled or pleated, with 4 short 
lobes and as many-small spreading horn-like processes: petals 4. caducous; 
stamens 4; style more than half as long as the capsule: capsule 4-celled. 
Wet places along the Columbia River and the Eastern States. 
A. humilis Michx. Fl. i, 99. Stems ascending, 2-10 inches high, 
branching from the base: leaves linear-oblong or lanceolate, obtuse, taper- 
ing below to a short petiole or sessile: flowers sessile or 2-3 in the lower 
axils; calyx 4-angled with 4 short lobes and as many small spreading pro- 
