AMARYLLIS FAMILY 



461 



4. Agave shawii Engelm. 



Shaw's Agave. 



Fig. 



1129. 



314. 



Agave shaivii Engelm. Trans. Acad. .St. Lo-nis 3: 

 />/. 2-4. 1875. 



Cespitose, shortly caulescent, scarcely 1 m. 

 high. Leaves ovate to lanceolate-ovate, acumi- 

 nate, 20-50 cm. long, 6-12 cm. wide, smooth, 

 glossy green, openly concave, stiffly erect com- 

 pact, and rather closely imbricated ; spine thick, 

 2-4 cm. long, 3-6 cm. wide, reddish, very openly 

 grooved almost to the end; prickles stout 10-15 

 mm. long, abruptly widened to about 10 mm. 

 at base, the intervening space repand, usually 

 continuously horny ; scape about 3 m. high, stout, 

 the upper third or less ovoid-paniculate ; bracts 

 deltoid, crowded and subimbricate, appressed ; 

 branches few, stout, nearly horizontal, simple or 

 three-branched with almost capitate bracted 

 flower-clusters ; pedicels very stout, much thick- 

 ened in fruit; flowers 7-9 cm. long, greenish 

 yellow, slightly fetid ; ovary subfusiform, 3-4 

 cm. long ; segments attenuate from a wide base, 

 20 mm. long, 8 mm. wide ; stamens inserted at 

 about the middle of the tube, 55-60 mm. long; 

 capsule oblong, 5-7 cm. long, 20-25 mm. thick, 

 with thick exocarp ; seed 7-9 mm. in diameter. 



Dry hillsides near the sea, south of San Diego, California. Type locality: on the international bou 

 near the Initial Boundary Monument. The only locality known for this rare plant. 



ndary, 



Family 22. IRIDACEAE. 



Iris Family. 



Perennial herbs arising from bulbs or commonly from rootstocks, with narrow 

 equitant 2-ranked leaves and perfect regular or irregular bracted flowers. Perianth 

 of 6 segments or 6-lobed, its tube adnate to the ovary, the segments or lobes in two 

 series of 3 each, convolute in the bud, withering-persistent. Stamens 3, inserted 

 opposite the outer segments or lobes ; filaments filiform separate or united ; 

 anthers 2-celled extrorse. Ovary inferior, mostly 3-celled ; ovules usually numer- 

 ous in each cavity, anatropous ; style 3-cleft, its lobes sometimes divided. Fruit a 

 3-celled, 3-angled or 3-lobed (sometimes 6-lobed), loculicidally dehiscent capsule. 

 Seeds numerous in 1 or 2 rows in each cavity of the capsule. Endosperm fleshy or 

 horny ; embryo straight, small. 



About 57 genera and 1000 species, widely distributed in temperate and tropical regions of both hemispheres. 



Styles petal-like; flowers very large, the two series of perianth-segments unlike. 

 Styles filiform; the two series of perianth-segments similar. 

 Filaments united to the top; flowers usually blue. 

 Filaments not united to the top; flowers not blue. 



Filaments united only at the base; flowers reddish purple. 

 Filaments united for more than half their length; flowers yellow. 



1. Iris. 



2. Sisyi'inchium. 



3. Olsyiiiiiin. 



4. Hvdastvhis. 



1. IRIS [Tourn.] L. Sp. PI. 38. 1753. 



Perennial herbs with creeping, often woody and sometimes tuber-bearing rootstocks, 

 erect stems, erect or ascending equitant leaves, and large regular flowers in terminal racemes 

 or sometimes panicles. Perianth of 6 clawed segments, united below into a tube, the 3 outer 

 segments broad, spreading or reflexed, the 3 inner usually narrower and erect. Stamens 

 inserted at the base of the outer perianth-segments ; anthers linear or oblong. Ovary 3- 

 celled ; divisions of the style petal-like, arching over the stamens, bearing the stigm.atic 

 surface on the inner surface on a flat scale immediately below the usually 2-lobed tip ; 

 style-base adnate to the perianth-tube. Capsule oblong or oval, 3-6-angled or lobed, mostly 

 coriaceous. Seeds numerous, vertically compressed, in 1 or 2 rows in each cavity. 

 [Greek, rainbow, referring to the variegated flowers.] 



About 100 species, mostly in the north temperate 2one. Besides the following about 15 species occur in 

 the eastern United States. Type species. Iris germanica L. 



