MUSTARD FAMILY 17 



thin partition stretched between the opposite parietal placentae ; ovules 1 to many, 

 in 1 or 2 rows, in either case their funiculi always attached alternately right and left 

 to the two placentae; style 1; stigma 2-lobed or entire. Fruit a 2-celled capsule, 

 the 2 valves separating from below upwards, leaving behind the placentae and 

 partition, or often 1-celled and indehiscent, or infrequently breaking up trans- 

 versely into 1-seeded joints. Capsule long and narrow (a silique) or short and 

 roundish (a silicle), commonly termed a pod and either terete, 4-sided, compressed 

 (flattened parallel to the partition) or obeompressed (flattened contrary to the 

 partition) . Seeds in 1 or 2 rows in each cell. Embryo always curved, the caulicle 

 folded upon the back of one of the cotyledons (incumbent) or along the edge of the 

 cotyledons (accumbent). — Herbage always with the characteristic mustard-like 

 or pungent juice. The petals are sometimes none. Some Streptanthus species 

 have a somewhat irregular flower. Platyspermum has solitary flowers. Tropido- 

 carpum has a leafy raceme. — Species 1500, all continents, both low and high alti- 

 tudes, but mostly in temperate and arctic zones. 



The early view of Lindley (Introd. Nat. Sys. 14, — 1830) and the later one of G. Henslow 

 (Trans. Linn. Soc. ser. 2, 1 :191 — 1876) that the flower is 4-merous throughout, and not 2-nierous 

 as held by perhaps the majority of botanists, is confirmed (although on different grounds) and 

 well established by recent investigations undertaken by Eames and "Wilson on the character and 

 course of the vascular bundles in the flower (Am. Jour. Bot. 17: 638-656, figs. 1-9, — 1930). The 

 contrasting theory of carpel polymorphism of Edith E. Saunders rests in the beginning upon 

 research conducted upon Matthiola (Ann. Bot. 39:123-167, — 1925), but extended to many other 

 genera. An historical note on early views as to the nature of the Cruciferous flower is given in 

 LeMaout and Decaisne, Sys. Bot. 229-230 (1873). 



Bibliog. — Brown, Eobert, Genera et species plantarum Cruciferarum (Misc. Bot. Works, 

 2: 367-413, — 1812). Watson, Sereno, Eevisions of Lesquerella and of the N. A. species of Draba 

 (Proc. Am. Acad. 23:249-260,-1888). Greene, E. L., Cruciferae [of middle Cal.] (Fl. Fr. 

 247-278, — 1891); Distribution of some western plants (Erythea 1:181-182, — 1893); Eevision 

 of Tropidocarpum (Proc. Acad. Phila. 1895:551-554, — 1895); studies in the Cruciferae. — 

 Cardamine and Dentaria (Pitt. 3:117-138, — 1896) ; Certain species of Arabis (Pitt. 4: 187-198,— 

 1900); Miscellaneous new species (Pitt. 4:198-203, — 1900); Type of the genus Draba (Pitt. 

 3:203-205,-1900); A proposed new genus Abdra (Pitt. 4:205-207,-1900); New species of 

 Lesquerella (Pitt. 4:307-311,-1901); Miscellaneous new species (Pitt. 4:311-315,-1901); 

 Certain West American Cruciferae (Lflts. 1: 81-90, — 1904) ; The genus Eadicula (Lflts. 1: 113- 

 114, — 1905); Icianthus and Sprengeria (Lflts. 1:197-199, — 1905); Some western species of 

 Arabis (Lflts. 2:69-83,-1910); Certain Cruciferous types (Lflts. 2:219-221,-1912). David- 

 son, A., Cruciferae of Los Angeles Co. (Erythea 2: 177-180, — 1894). Dewey, L. H., Tumbling 

 Mustard (U. S. Dept. Agr. Div. Bot. Circ. '7, pp. 1-8, figs. 1-3,-1896). Eobinson, B. L., The 

 fruit of Tropidocarpum (Erythea4:109-119, pi. 3, — 1896) ; Two varieties of Sisymbrium officinale 

 in America (Ehod. 7:101-103, — 1905). Pammel, L. H., Weeds of the Mustard Family (Iowa 

 Agr. Exp. Sta. Bull. 34: 656-686, pis. 1-15, — 1897). Eastwood, A., A study of Erysimum grandi- 

 floruan Nutt. (Zoe, 5:100-103, — 1901). Gunthart, A., Beitrage zur Blutenbiologie der Crueiferen 

 (Biblio. Bot. ll^:i-ix, 1-38,-1902). Schulz, O. E., Monog. der Gatt. Cardamine (Engler, 

 Bot. Jahrb. 32:280-623,-1903); Cruciferae-Brassiceae (Engler, Pflzr. 4^^:1:1-290, figs. 

 1-35,-1919; 4^''^:2:1-100, figs. 1-26,-1923); Sisymbrieae (Engler, Pflzr. 4:^"^ :1-Z88, figs. 

 1-74,-1924); Draba et Erophila (Engler, Pflzr. 4>'>^:1-Z96, flgs. 1-35,-1927). Bayer, A., 

 Beitrage zur systematischen Gliederung der Crueiferen (Bot. Centralbl. beih. 18, abt. 2:119- 

 180,-1905). Nelson, A., Note on Arabis pedicellata (Proc. Biol. Soc. Wash. 18: 187,-1905). 

 Thellung, Albert, Die Gatt. Lepidium (Mitteil. Bot. Mus. Univ. Zurich 28: 1-340,— 1906). Eyd- 

 berg, P. A., Thelypodium (Bull. Torr. Club 34: 428-435,— 1907). Von Hayek, A., Entwurf eines 

 Cruciferen-Systems auf phylogenetischer Grimdlage (Bot. Centralbl. beih. 27:127-335, t. 8-12, 

 —1911). Payson, E. B., The perennial scapose Drabas of N. Am. (Am. Jour. Bot. 4:253-267,— 

 1917); Notes on certain Cruciferae (Ann. Mo. Bot. Gard. 5:143-151, — 1918); Monograph of 

 the genus Lesquerella (I.e. 8:103-236, figs. 1-34, — 1921) ; A monographic study of Thelypodium 

 and its immediate allies (I.e. 9:233-324, — 1922); The genus Thlaspi in N. Am. (Univ. Wyo. 

 Publ. Sci. Bot. 1:145-163, figs. 8-15,-1926). Fernald, M. L., Some variations of CakUe eden- 

 tula (Ehod. 24:21-23, — 1922). M. K. Bellu'e, New weeds confused with Hoary Cress (Mo. Bull. 

 Cal. Dept. Agr. 22:288-293, figs. 1-3,-1933). 



