428 CALLITRICHACE^. (WATER-STARWORTS.) 



senting the most reduced form of the Halorageae, p. 174. The so-called 

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

 inate and one j)istillate naked flowers in the same axil, each of a single 

 stamen or pistil.) 



The elaboration of our species is contributed by Du. G. Engelmanx. 



1. CALLITRICHE, L. Watek-Starwort. 



Flowers moncecious, solitary or 2 or 3 together in the axil of the same leaf, 

 wholly naked or between a pair 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-cclled 

 ovary, either sessile or pcdicclled, 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 : cnd)ryo slender, straight or slightly 

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

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

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

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

 the commoner species.) 



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

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

 wedge-shaped, 3-nerved, crowded, provided with stomata : jUament iwt 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 reflcxed ; 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 l"-2" long: fruit J'' in diameter. 



C. PEPLOiDES, Nutt. and C. Nuttallii, 7orr. (C. pedunculbsa, Nutt.), — 

 the former with subsessile curiously gibbous fruit, the latter with long-pcduncled 

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



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

 ten-estrial as in the former, or wholly sttbmersed as in the next section) : haves 

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

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

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



2. C v6rna, L. Fruit (-}" long) higher than broad, obovate, slightly ob- 

 cordate, usually thicker at the base than ujjwards, 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 iuto a petiole. — Common in stagnant 

 waters, from Pennsylvania and New Jersey north and northwestwai-d. April - 



