622 



MENYANTHACEAE. 



[Vol.. II. 



i. Menyanthes trifolislta L. Buckbean. Marsh or Bean Trefoil. Bog-bean. 



(Fig. 2889.) 



Menyanthes trifoliata I,. Sp. PI. 145. 1753. 



Rootstock thick, scaly, sometimes i long, 

 marked by the scars of bases of former petioles. 

 Leaves 3-foliolate; petioles sheathing at the base, 

 2 / -io / long; leaflets oblong or obovate, entire, 

 obtuse at the apex, narrowed to the sessile base, 

 pinnately veined, i^'-S' long; raceme borne on 

 a long scape-like naked peduncle, arising from 

 the rootstock, io-2o-flowered; pedicels stout, 

 3 // -i2 // long, bracteolate at the base; flowers 

 $"-6" long; calyx shorter than the white or 

 purplish corolla, which is bearded with white 

 hairs within; stamens shorter than the corolla 

 and style exserted, or longer and style nearly 

 included; capsule ovoid, obtuse, about 4" long. 



In bogs, Greenland to Alaska, south to 

 Island, Pennsylvania, Minnesota and California. 

 Also in Europe and Asia. May-July. 



2. LIMNANTHEMUM S. G. Gmelin, Nov. Act. Acad. Petrop. 14: 527. 



//. 77. /. 2. 1769. 



Aquatic perennial herbs, with slender rootstocks. Leaves floating, petioled, ovate or or- 

 bicular, deeply cordate, entire or repand, or the primary ones different; flowers yellow, or 

 white, umbellate at the summit of filiform stems at the bases of the petioles, or axillary, often 

 accompanied by a cluster of thick elongated root-like tubers. Calyx 5-parted. Corolla 

 nearly rotate, deeply 5-cleft, the lobes induplicate-valvate in the bud, sometimes finilni :iU- 

 on the margins. Stamens 5, inserted on the base of the corolla; filaments short; anthers 

 sagittate, versatile. Ovary i -celled; style short or none; stigma 2-lamellate. Capsule ovoid 

 or oblong, indchiscent or irregularly bursting. Seeds numerous or few, smooth or rough. 

 [Greek, pool-blossom.] 



About 20 species, widely distributed in temperate and tropical regions. The following are the 

 only ones known to occur in North America. 



Flowers accompanied by tufts of root-like tubers; native species. 



Floating leaves i' -2 long; flowers 3" -6" broad, yellow; seeds smooth. i. L. lacunosum. 



Floating leaves 2' -6' long; flowers 6"-io" broad, white; seeds rough. 2. L. aquaticum. 

 Flowers not accompanied by tufts of tubers; flowers bright yellow, i broad, or more; introduced 

 species. 3. /,. nymphaeoides. 



i. Limnanthemum lacundsum (Vent.) 

 Griseb. Floating Heart. (Fig. 2890.) 



Villarsia lacunosa Vent. Choix des Plantes, 9. 1803. 

 Limnanthemum lacunosum Griseb. Gent. 347. 1839. 



Rootstock buried in the mud, the roots long and 

 fibrous. Primary leaves membranous, submerged, 

 short-petioled; stems (stolons) filiform, greatly elon- 

 gated, sometimes 10 long, bearing a short-petioled 

 floating leaf, an umbel of flowers and a cluster of nar- 

 row tubers at its summit, or some of the floating 

 leaves on petioles as long as the stems; floating leaves 

 ovate-orbicular, purplish beneath, i / -2 / long, the basal 

 sinus narrow or broad; pedicels slender; tubers linear- 

 conic, %'-\' long; flowers yellow, $"-&' broad; style 

 none; capsule ovoid, covered by the connivent calyx- 

 segments; seeds numerous, smooth. 



In ponds, Nova Scotia to Florida, west to Ontario, Min- 

 nesota and Louisiana. July-Aug. 







