Vol. I. GENERAL KEY TO THE ORDERS AND FAMILIES. xxiii 



Carpels distinct. Order 3. Alismales. 



Petals similar to the sepals; anthers mostly elongated. Fam. 6. Scheuchseriaceae. 1: 91. 



Petals not similar to the sepals ; anthers short. Fam. 7. Alismaceae. 1 : 93. 



Carpels united. Order 4. Hydrocharitales. 



Ovary 1 -celled with parietal placentae. Fam. 8. Vallisneriaceae. 1 : 104. 



Ovary 6-9-celled. Fam. 9. Hydrocharitaceae. 1 : 106. 

 tt Flowers in the axils of dry chaffy scales (glumes), arranged in spikes or spikelets. 



Orders. Graminales {Glumiflorae) . 



Fruit a caryopsis (grain) ; stems (culms) mostly hollow in our species. Fam. 10: Gr amine ae. 1 : 107. 



Fruit an achene; stems (culms) solid. Fam. 11. Cyperaceae. 1 : 295. 



(Order 6, Palmales, including only the family Palmaceae, Palms, and Order 7, Cyclanthales, 



including only the family Cyclanthaceae, are not represented in our territory.) 



** Inflorescence a fleshy spadix, with or without a spathe ; or plants 'minute, floating free, .the flowers few or 

 solitary on the margin or back of the thallus. 



Order 8. Arales (Spathiflorae) . 

 Large herbs, with normal foliage and well-developed spadix. Fam. 12. Araceae. 1 : 441. 



Minute floating thalloid plants. Fam. 13. Lemnaceae. 1:446. 



2. Carpels united into a compound ovary; parts of the usually complete flowers mostly in 3's or 6 s. 



* Seeds with endosperm. 



t Flowers regular, or nearly so (corolla irregular in Commelina and Pontederia). 

 X Endosperm mealy ; ovary superior. 



Order 9. Xyridales (Farinosae). 



a. Ovary 1 -celled. 



Aquatic moss-like leafy herbs ; flowers solitary. Fam. 14. Mayacaceae. 1 : 450. 



Erect rush-like herbs; flowers in terminal scaly heads or spikes. Fam. 15. Xyridaceae. 1 : 450. 



Mud or aquatic herbs, the flowers subtended by spathes (Heteranthera in Pontederiaceae I: 462). 



b. Ovary 2-3-celIed (except in some Pontederiaceae). 

 Flowers very small, densely capitate, monoecious or dioecious. Fam. 16. Eriocaulaceae. 1 : 453. 



Flowers perfect. 



Epiphytes ; leaves scurfy. Fam. 17. Bromeliaceae. 1:456. 



Terrestrial or aquatic herbs ; leaves not scurfy. 



Perianth of 2 series of parts, the outer (sepals) green, the inner (petals) colored. 



Fam. 18. Commelinaceae. 1 : 457. 

 Perianth 6-parted. Fam. 19. Pontederiaceae. 1 : 462. 



tt Endosperm fleshy or horny; ovary superior or inferior. 



Order 10. Liliales. 



a. Ovary superior (except in Aletris, in the Liliaceae, and some species of Zygadenus in the 



Melanthaceae). 

 Perianth-segments distinct, green or brown, not petal-like ; herbs with grass-like leaves and small 

 flowers. Fam. 20. Juncaceae. 1 : 465. 



Perianth-segments distinct, or partly united, at least the inner petal-like. 



Fruit a capsule (except in Yucca baccata, where it is large, fleshy and indehiscent). 



Capsule mostly septicidal ; plants rarely bulbous. Fam. 21. Melanthaceae. 1:485. 



Capsule loculicidal (septicidal in Calochortus) ; plants mostly bulbous. 



Fam. 22. Liliaceae. 1 : 495. 

 Fruit a fleshy berry (except in Uvularia of the Convallariaceae). 

 Erect herbs ; tendrils none ; flowers perfect. 



Leaves basal or alternate. Fam. 23. Convallariaceae. 1:513. 



Leaves verticillate. Fam. 24. Trilliaceae. r : 522. 



Vines, climbing by tendrils, or rarely erect ; flowers dioecious, in axillary umbels. 



Fam. 25. Smilaceae. 1 : 526. 



b. Qvary inferior, wholly or in part. 



Stamens 3, opposite the inner corolla-segments. Fam. 26. Haemodoraceae. 1 : 530. 

 Stamens 6 in our species. 



Erect perennial herbs ; flowers perfect. Fam. 27. Amarylhdaceae. 1 : 531. 



Twining vines ; flowers dioecious. Fam. 28. Dwscoraceae. 1 : 535. 



Stamens 3, opposite the outer corolla-segments. Fam. 29. Iridaceae. 1 : 536. 

 tt Flowers very irregular; ovary inferior. 



Order 11. Scitaminales. 



One family represented in our territory. Fam. 30. Marantaceae. 1 : 546. 

 ** Seeds without endosperm, very numerous and minute ; ovary inferior. 



Order. 12. Orchidales (Microspermae) . 



Flowers regular; stem-leaves reduced to scales. Fam. 31. Burmanniaceae. 1 : 546. 



Flowers very irregular. Fam. 32. Orchidaceae. 1 : 547. 



Subclass 2. Dicotyledones. i : 577. 



Embryo normally with 2 cotyledones ; stems mostly differentiated into pith, wood and bark; 



leaves mostly net-veined. 

 Series 1. Choripetalae. i : 577 to 2 : 666. 

 Petals distinct to the base, or wanting (exceptions noted Vol. 1 : 57>)- 

 A. Petals none, except in Port'ulacaceae and in most Caryophyllaceae, which are herbs with leaves 

 nearly always opposite, the seeds with endosperm, and in the pistillate flowers of the walnuts 

 0uglans). 

 1. Calyx none (except in the Juglandaceae, which are trees with odd-pinnate leaves). 

 Marsh herbs with perfect flowers in nodding spikes. Order 1. Piperales. 



