CONVOLVULACEJE. (CONVOLVULUS FAMILY.) 371 



4-ovuled ; styles distinct, or rarely united. Capsule mostly 4-seeded. Em- 

 bryo thread-shaped, spirally coiled in the rather fleshy albumen, destitute of 

 cotyledons, sometimes with a few alternate scales (belonging to the plumule) ; 

 germination occurring in the soil. Leafless annual herbs, with thread-like 

 yellowish or reddish stems, bearing a few minute scales in place of leaves ; 

 on rising from the ground becoming entirely parasitic on the bark of herbs 

 and shrubs on which they twine, and to which they adhere by means of suck- 

 ers developed on the surface in contact. Flowers small, cymose-clustered, 

 mostly white ; usually produced late in summer and in autumn. (Name sup- 

 posed to be of Arabic derivation.) 



1. Stigmas elongated ; capsule circumscissile. 



C. EpfLiNUM, Weihe. (FLAX DODDER.) Stems very slender, low; flowers 

 globular, sessile in dense scattered heads ; corolla 5-parted, short-cylindrical, 

 scarcely exceeding the broadly ovate acute divisions of the calyx, persistent 

 around the capsule ; stamens included ; scales short, broad, crenulate, shorter 

 than the globose ovary. Flax-fields; in Europe very injurious; sparingly 

 introduced with flax-seed into the Northern States. June. 



C. EpfTHYMUM, Murr. Stems very slender; flowers capitate; corolla-lobes 

 spreading, the cylindrical tube longer than the suberect acute sepals ; scales 

 large, contiguous, toothed ; stamens exserted. Occasionally found in clover- 

 fields. (Int. from Eu.) 



2. Stigmas capitate ; capsule indehiscent. 



* Calyx gamosepalous ; ovary and capsule depressed-globose. 



+- Flowers in dense or globular clusters ; corolla with short and wide tube, per 



sistent at the base of the capsule ; styles mostly shorter than the ovary. 



1. C. Chlorocarpa, Engelm. Stems coarse, orange-colored; flowers 

 white (1 - li" long) ; lobes of calyx and corolla (mostly 4) acute, often longer 

 than the tube ; scales small, 2-cleft, often reduced to a few teeth ; the thin cap- 

 sule pale greenish-yellow. Wet places, from Wise, and Minn, to Ark. ; also 

 in Penn. and Del., often on Polygonum. 



2. C. arv6nsis, Beyrich. Stems pale and slender, low ; Jlowers smaller 

 (hardly 1" long) ; calyx-lobes (5) obtuse, mostly very broad ; those of the corolla 

 acuminate, longer than the tube, with inflexed points; scales large, deeply 

 fringed. Kather dry soil on various low plants, N. Y. to Fla., west to the 

 Pacific. Very variable. 



- *- Flowers in panicled often compound cymes ; styles slender, mostly longer 

 than the ovary ; corolla withering on the summit of the large capsule. 



3. C. tenuiflbra, Engelm. Stems coarse and yellow, usually rather high- 

 climbing; flowers (T'long or less) on short thick pedicels, often 4-merous ; 

 lobes of calyx and corolla oblong, obtuse, the latter mostly shorter than the 

 slender deeply campanulate tube ; scales shorter than the tube, fringed. On 

 tall herbs and shrubs in wet places, Penn. to Minn., and south to Tex. 



# * Calyx gamosepalous; ovary and capsule pointed, the latter enveloped or 

 capped by the marcescent corolla ; Jlowers in loose panicled cymes. 



-H- Acute tips of the corolla-lobes inflexed. 



4. C. dec6ra, Engelm. Stems coarse ; flowers fleshy and more or lesi 

 papillose; calyx-lobes triangular, acute; those of the broadly campanulate 



