PASSIFLORACE^E. (PASSION-FLOWER FAMILY.) 185 



1. OPUNTIA, Tourn. Prickly Pear. Indian Fig. 



Sepals and petals not united into a prolonged tube, spreading, regular, the 

 inner roundish. Berry often prickly. Seeds flat and margined. Embryo 

 coiled around albumen : cotyledons large, foliaceous in germination. — Stem 

 composed of joints, bearing very small awl-shaped and usually deciduous leaves 

 arranged in a spiral order, with clusters of barbed bristles and often spines also 

 in their axils. Flowers in our species yellow, opening in sunshine for more than 

 one day. (A name of Theophrastus, originally belonging to some different 

 plant.) 



1. O. vulgaris, Mill. (Cactus Opuntia, L.) Low, prostrate or spreading, 

 pale, with flat and broadly obovate joints ; the minute leaves ovate-subulate and 

 appresscd; the axils bristly, rarely Avith a few small spines; flowers sulphur-yel- 

 low ; berry nearly smooth, pulpy, eatable. — Sandy fields and dry rocks, from 

 Nantucket, Mass., southward, usually near the coast. June. 



2. O. Rafinesquii, Engelm. Joints (deep green) and flowers larger than 

 in the preceding, the latter often with a red centre, and with more numerous 

 (10-12) petals; leaves spreading, longer and narrower (3" -4") ; axils some of 

 them bearing a few small spines and a single strong one (9" -12" long). — 

 Wisconsin to Kentucky and westward. June. 



3. O. Missouriensis, DC. Prostrate; the joints broadly obovate and 

 flat (2' -4' long), tuberculate; leaves minute; axils armed with a tuft of straw- 

 colored bristles and 5 - 10 slender radiating spines (1 '-2' long); flowers light 

 yellow; berry dry, prickly. — Borders of Wisconsin and westward. May- July. 



Order 44. PASSIFLORACE^E. (Passion-Flower Family.) 



Herbs or woody plants, climbing by tendrils, with perfect flowers, 5 mona- 

 delphous stamens, and a stalked l-celled ovary free from the calyx, with 3 or 

 4 parietal placentas, and as many club-shaped styles ; — represented by the 

 typical genus 



1. PASSIPLORA, L. Passion-Flower. 



Calyx of 5 sepals united at the base into a short cup, imbricated in the bud, 

 usually colored like the petals, at least within; the throat crowned with a double 

 or triple fringe. Petals 5, on the throat of the calyx. Stamens 5 : filaments 

 united in a tube which sheathes the long stalk of the ovary, separate above : 

 anthers large, fixed by the middle. Berry (often edible) many-seeded ; the ana- 

 tropous albuminous seeds invested by a pulpy covering. Seed-coat brittle, 

 grooved. — Leaves alternate, generally palmately lobed, with stipules. Pedun- 

 cles axillary, jointed. Ours are perennial herbs. (Name, from />assio, passion, 

 and fios, a flower, given by the early missionaries in South America to these 

 blossoms, in which they fancied a representation of the implements of the cru- 

 cifixion.) 



1. P. lutea, L. Smooth, slender; leaves obtusely 3-lobed at the summit, the 

 lobes entire; petioles glandless; flowers greenish-yellow (1' broad). — Damp 

 thickets, S. Penn. to 111. and southward. July - Sept. — Fruit $ in diameter. 

 L & M— 28 



