CAPPARIDACEAE. 169 



1. Cleomella angustifolia Torr. In valley, especially in sandy or alkaline 

 soil, from Neb. and Utah to Tex. — Headwaters of Clear Creek ; Julesburg. 



2. Cleomella oocarpa A. Gray. In alkaline plains and desert regions from 

 Colo, to Calif. — Mesa Verde, about Rio Mancos (Brandcgee) . 



Order 27. ROSALES. 



Flowers regular or nearly so (actinomorphic). 



Endosperm present usually copious and fleshy ; stipules mostly wanting. 

 Herbs. 



Carpels as many as the sepals ; succulent plants. 



Fam. 61. Crassulaceae. 

 Carpels fewer than the sepals ; plant scarcely succulent. 



Staminodia wanting; carpels 2 or rarely 3, distinct or only partly united. 



Fam. 62. Saxifragaceae. 

 Staminodia present ; carpels 3 or 4, wholly united into a i -celled gynoecium. 



Fam. 63. Parnassiaceae. 

 Shrubs or trees. 



Leaves opposite ; fruit a leathery capsule, more or less adnate to the hypan- 



thium ; stipules wanting. Fam. 64. Hydrangiaceae. 



Leaves alternate. 



Fruit thin-walled follicles, free from the hypanthium ; stipules present 



(Opulaster in) Fam. 66. Rosaceae. 



Fruit a berry ; hypanthium adnate to and prolonged beyond the ovary. 



Fam. 65. Grossulariaceae. 

 Endosperm wanting or scant ; stipules mostly present. 



Carpels several or numerous, or, if solitary, becoming an achene. 



Carpels distinct, free from the hypanthium ; fruit achenes, follicles or 



drupelets. Fam. 66. Rosaceae. 



Carpels united, enclosed by and adnate to the hypanthium ; fruit a pome. 



Fam. 67. Malaceae. 

 Carpel solitary, not becoming an achene. 



Ovary 2-ovuled ; fruit a drupe ; leaves simple. Fam. 68. Amygdalaceae. 

 Ovary several-ovuled ; fruit a legume ; leaves pinnately compound. 



Fam. 69. Mimosaceae. 

 Flowers irregular (mostly zygomorphic). 



Upper petal enclosed by the lateral ones in the bud ; corolla not papilionaceous. 



Fam. 70. Cassiaceae. 

 Upper petal enclosing the lateral ones in bud ; corolla papilionaceous. 



Fam. 71. Fabaceae. 



Family 61. CRASSULACEAE DC. Orpine Family. 



Stamens as many as the sepals; minute herbs. i. Tillaeastrum. 



Stamens twice as manj^ as the sepals ; succulent herbs. 



Flowers axillary in dense congested racemes ; petals rose-colored. 



2. Clementsi.\. 

 Flowers terminal, arranged in one-sided raceme-like branches. 



Carpels erect ; flowers polygamous or dioecious ; petals in ours purplish. 



3. Rhodiola. 

 Carpels spreading ; flowers perfect ; petals in ours yellow. 4. Sedum. 



I. TILLAEASTRUM Britton. Pigmy-weed. 



I. Tillaeastrum aquaticum (L.) Britt. {Tillaea aquatica L. ; T. angusti- 

 folia Nutt.) On muddy shores from N. S. and Wash, to Md., La. and Lower 

 Calif. — Alt. up to 10,000 ft.- — Twin Lakes. 



