SCROPHULARIACEAE. 831 



16. MICRANTHEMUM Michx. 



Creeping or ascending, small leafy annual glabrous herbs, with opposite obovate, 

 oval or orbicular sessile entire leaves, and minute white or purplish short-peduncled 

 flowers, solitary in the axils. Calyx 4-5-lobed or 4-5 -parted. Corolla irregular, 

 the tube short, the upper lip shorter than the lower, or wanting, the lower 3-lobed, 

 the middle lobe the largest. Stamens 2, anterior; filaments short, somewhat dilated 

 or appendaged at the base; anthers small, their sacs distinct, parallel, of slightly 

 divergent. Style short; stigma 2-lobed. Capsule globose, 2 -celled by a membra- 

 nous partition or becoming i-celled. Seeds numerous, minute. [Greek, small 

 flower.] About 16 species, natives of America. Besides the following, another 

 occurs in the southern U. S. 



i. Micranthemum micranthemoides (Nutt.) Wettst. NUTTALL'S MICRAN- 

 THEMUM. (I. F. f. 3282.) Somewhat fleshy; stein filiform, creeping, the branches 

 ascending, 1-6 cm. high. Leaves obovate to oval, obtuse, 2-5 mm. long; flowers 

 about I mm. long, on peduncles of about the same length; calyx campanulate in 

 flower, obovoid in fruit, 4-lobed, usually split along one side; peduncles recurved 

 in fruit; upper lip of the corolla nearly obsolete; middle lobe of the lower lip longer 

 than the lateral ones; appendages at the bases of the stamens nearly as long as the 

 filaments; stigma of 2 subulate lobes; capsule obovoid-globose, I mm. in diameter, 

 as long as the calyx. In tidal mud, N. J. to Fla. Also in Cuba. Aug-Oct. 



17. LIMOSELLA L. 



Low glabrous succulent floating or creeping, tufted annual herbs (or perennial 

 by stolons ?), with filiform stems rooting at their nodes, basal slender-petioled_entire 

 leaves, and filiform I -flowered scape-like peduncles, the flowers small, white, pink, 

 or purple. Calyx campanulate. 5-lobed. Corolla nearly regular, open-campanu- 

 late, the tube short, the limb 5 -cleft. Stamens 4, inserted on the corolla-tube, 

 scarcely exserted; filaments short; anther-sacs confluent. Style short; stigma cap- 

 itate. Ovary 2-celled at the base, I -celled above. Capsule globose or oblong, be- 

 coming i-celled, many- seeded. [Greek, mud-seated.] About 6 species, of wide 

 distribution. 



Leaves expanded above into an oblong or linear-oblong blade. i. L. aquatica. 



Leaves filiform-linear, with little or no distinction between blade and petiole. 



2 L. tenuifolia. 



1. Limosella aquatica L. MUDWEED. MUDWORT. (I. F. f. 3283.) 

 Leaves 2-13 cm. long, the blade obtuse, one-fourth or one-third as long as the 

 filiform petiole. Peduncles shorter than the leaves, arising from the base of the 

 plant or from nodes of the stem; corolla pink or white, about 2 mm. broad, scarcely 

 longer than the calyx; calyx-lobes ovate, acute or acutish. about the length of the 

 tube; stamens inserted on the corolla-tube; filaments somewhat longer than the 

 anthers; capsule obtuse, 3 mm. high, longer than the calyx. On muddy shores 

 and in brooks, Lab. and Hudson Bay to the N. W. Terr., Colo, and Cal. Also in 

 Europe, Australia and S. Am. June-Aug. 



2. Limosella tenuifolia Hoffm. NARROW-LEAVED MUDWORT. (I. F. f. 

 3284.) Similar to the preceding but usually smaller, the leaves seldom over 4 cm. 

 high, linear- filiform, with no distinction between blade and petiole, or sometimes 

 slightly expanded toward the apex. In brackish mud, Lab. to N. J. Also in 

 Europe, Australia and S. Am. Summer. 



18. SYNTHYRIS Benth. 



Perennial herbs, with thick rootstocks, simple erect stems, large petioled basal 

 leaves, those of the stem much smaller, alternate, sessile, or clasping, bract-like. 

 Flowers small, pink or purple, in terminal dense spikes or racemes. Calyx 4-5- 

 parted. Corolla oblong or campanulate, 2-4-lobed, or parted, or wanting, the 

 lateral lobes, when present, exterior in the bud. Stamens 2 (occasionally 4), pos- 

 terior, inserted on the corolla, or on the outer side of the hypogynous disk, ex- 

 serted; filaments slender. Ovary 2-celled or rarely 3-celled; style filiform; stigma 

 capitate. Capsule compressed, obtuse, or emarginate, many-seeded, loculicidally 

 dehiscent, its valves adhering to the axis of the placentae; seeds flat, oval, or or- 

 bicular. [Greek, doors closed, alluding to the capsule-valves] About 10 species, 



