182 LYTHRACE^E. (LOOSESTRIFE FAMILY.) 



* * Anthers oblong, straight, without any spur : flowers few, sessile. 

 3. R. ciliosa, Michx. Stem square, glabrous; leaves broadly ovate, 

 ciliate with long bristles ; calyx glabrous. — Maryland and southward. 



Order 41. LYTHBACE^l. (Loosestrife Family.) 



Herbs, with mostly opposite entire leaves, no stipules, the calyx enclosing 

 but free from the 1 - ^-celled many-seeded ovary and membranous pod, and 

 bearing the 4-7 deciduous petals and 4-14 stamens on its throat ; the latter 

 lower down. Style 1 : stigma capitate, or rarely 2-lobed. — Flowers axillary 

 or whorled, rarely irregular, perfect, sometimes dimorphous or even tri- 

 morphous, those on different plants with filaments and style reciprocally 

 longer and shorter. Petals sometimes wanting. Pod often 1-celled by 

 the early breaking away of the thin partitions : placentae in the axis. 

 Seeds anatropous, without albumen. — Branches usually 4-sided. 



* Flowers regular, or nearly so. 



1. Ammannia. Calyx short, 4-angled, not striate. Petals 4, or none. Stamens 4, rarely 2. 



2. Lythrnm, Calyx tubular-cylindrical, striate. Petals 5-7. Stamens 5 -14. 



3. JVessea. Calyx short-campanulate or hemispherical. Stamens 10 - 14, exserted. 



* * Flowers irregular : petals unequal. 



4. Cuphea. Calyx spurred or enlarged on one side at the base. Stamens 12. 



1. AMMANNIA, Houston. Ammannia. 



Calyx globular or bell-shaped, 4-angled, 4-toothed, usually with a little horn- 

 shaped appendage at each sinus. Petals 4 (purplish), small and deciduous, 

 sometimes wanting. Stamens 4, rarely 2, short. Pod globular, 2 - 4-celled. 

 — Low and inconspicuous smooth herbs, with opposite narrow leaves, and small 

 greenish flowers in their axils, produced all summer. (Named after Paul 

 Ammann, a German botanist anterior to Linnaeus.) 



§ 1. Calyx with manifest tooth-like or horn-shaped appendages at the sinuses: pod 4- 

 celled : plants of low or wet ground ; ours are annuals. 



1. A. htimilis, Michx. Leaves tapering at the base or into a short petiole, 

 linear-oblanceolate or somewhat spatulate ; flowers solitary or 3 together in the 

 axils of the leaves, sessile ; style very short. — Massachusetts to Michigan, 

 Illinois and southward. 



2. A. latifdlia, L. Leaves linear -lanceolate (2' -3' long), ivith a broad 

 auricled sessile base; style sometimes very short, sometimes slender. — Ohio, 

 Illinois, and southward. Ship-yards, Philadelphia, an immigrant from the 

 south, C. F. Parker. 

 § 2. HYPOBRYCHIA, M. A. Curtis. Appendages at the sinuses of the calyx 



mere callous points or none : petals none : pod 1-celled. 



3. A. Nuttallii, Gray. Submersed aquatic, or sometimes terrestrial, 

 rooting in the mud ; leaves linear, when immersed elongated, thin, and closely 

 sessile by a broad base, when out of water shorter and contracted at the base ; 

 flowers mostly solitary in the axils, sessile, small ; calyx with broad triangular 

 lobes; style very short. (Peplis diandra, Null., but stamens usually 4- Hypo- 



