428 CALLITRICHACEtE. (water-starworts.) 



sentiiig the most reduced form of the Halorageae, p. 1 74. The so-called 

 perfect flower is considered to be a staminate and a pistillate, or two stam- 

 inate and one pistillate naked flowers in the same axil, each of a single 

 stamen or pistil.) 



The elaboration of our species is contributed by Dr. G. Engelmann. 



1, CALLITSICHE, L. Water-Starwort. 



Flowers monoecious, solitary or 2 or 3 together in the axil of the same leafj 

 wholly naked or between a pan* of membranaceous bracts. Sterile flower a sin- 

 gle stamen : filament bearing a heart-shaped 4-celled anther, which by confluence 

 becomes one-celled, and opens by a single slit. Fertile flower a single 4-celled 

 ovary, either sessile or pedicelled, bearing 2 distinct and filiform sessile, usually 

 persistent stigmas. Ovule solitary in each cell. Fruit nut-like, compressed, 4- 

 lobed, 4-celled, separating at maturity into as many closed 1-seeded portions. 

 Seed anatropous, suspended, filling the cell : embryo slender, straight or slightly 

 curved, in the axis and nearly the length of the oily albumen. — Smooth, or beset 

 with minute stellate scales (visible only under the microscope), with spatulateor 

 linear leaves, both forms often occurring on the same stem. (Name from icaKos, 

 beautiful, and 6pi£, hair, from the almost capillary and usually tufted stems of 

 the commoner species.) 



§ 1. Terrestrial species. Small annuals, forming tufts on merely moist soil; 

 destitute of stellate scales and of bracts : leaves uniform, very small, obovate or 

 wedge-shaped, 3-nerved, crowded, provided with stomuta : filament not lengthen- 

 ing : carpels connate. 



1. C. Austini, Engelm. Fruit small, broader than high, deeply notched 

 above and below, on a pedicel often nearly of its own length ; lobes of the fruit 

 narrowly winged and with a deep groove between them, wings denticulate ; per- 

 sistent stigmas shorter than the fruit, spreading or reflexed ; leaves obovate. — 

 On damp soil in open woods, fields and roads, New York and New Jersey ( C. F. 

 Austin) to Illinois, Missouri, Texas, Mexico, and South America. April- June. 

 ^.- Half an inch or an inch high : leaves 1" - 2" long : fruit £" in diameter. 



C. peploides, Nutt. and C. Nuttallii, Torr. (C. pedunculosa, Nutt.), — 

 the former with subsessilu curiously gibbous fruit, the latter with long-peduncled 

 fruit with eversed keels, - — are southwestern species of this section. 



§2. Amphibious species. Perennials? with elongated stems {occasionally quite 

 terrestrial as in the former, or ivholly submersed as in the next section) : leaves 

 with stellate scales and stomata, the floating ones obovate and 3-nerved, the sub- 

 mersed linear: fowers usually between a pair of bracts, rarely naked : pollen shed 

 only in the air ; the filament elongating afterwards : carpels in fruit connate. 



2. C. verna, L. Fruit (-£" long) higher than broad, obovate, slightly ob- 

 cordatc, usually thicker at the base than upwards, sessile, its lobes sharply keeled 

 or very narrowly winged upwards, and with a wide groove between them ; stig- 

 mas shorter than the fruit, almost erect, usually deciduous ; floating leaves 

 crowded in a tuft, obovate, narrowed, in to a petiole. — Common in stagnant 

 waters, from Pennsylvania and Ncav Jersey north and northwestward. April - 



