xxvi GENERAL KEY TO THE ORDERS AND FAMILIES. VOL. L 



a. Flowers regular. 

 Pistils usually several or numerous (one only in Cercocarpus and some species of Alchemilla and 



Aphanes ; in Sanguisorba, Poteridiuni and Poterium). 

 Carpels distinct, sometimes adnate to the calyx, ripening into follicles or achenes. 



Fam. 54. Rosaceae. 2 : 242. 

 Carpels united, enclosed by the calyx-tube and adnate to it, the fruit a pome. 



Fam. 55. Malaceae. 2 : 286. 

 Pistil only i. 



Ovary 2-ovuled ; fruit a drupe; leaves simple. Fam. 56. Amygdalaceae. 2: 322. 



Ovary several-ovuled ; fruit a legume; leaves 2-3-pinnate. Fam. 57. Mimosaceae. 2: 330. 



b. Flowers irregular (nearly or quite regular in Gleditsia and Gymnocladus. 

 trees of the Caesalpiniaceae). 



Fruit a legume ; upper petal enclosed by the lateral ones in the bud ; leaves compound, mostly 

 stipulate. Fam. 58. Caesalpiniaceae. 2 : 334. 



Fruit spiny, indehiscent ; leaves simple, exstipulate. Fam. 59. Krameriaceae. 2: 340. 



Fruit a legume or loment ; upper petal enclosing the lateral ones in the bud ; leaves compound 

 (sometimes i-foliolate), stipulate. Fam. 60. Fabaceae. 2:341. 



4. Carpels united into a compound ovary; sepals mostly distinct. 

 * Stamens few, rarely more than twice as many as the sepals. 



t Stamens as many as the sepals or fewer, and opposite them, or more numerous. 

 % Ovules mostly pendulous, with the raphe toward the axis of the ovary. 



Order 16. GERANIALES. 

 Stamens more than one ; land plants. 



Filaments partially united (distinct in some Geraniaceae) ; herbs, the leaves not punctate. 

 Leaves not pinnately compound. 



Capsule at length splitting into its 5 carpels ; leaves lobed or dissected. 



Fam. 61. Geraniaceae. 2:425. 

 Capsule 2-s-celled, not splitting into its carpels. 



Stamens 2-3 times as many as the petals ; leaves 3-foliolate in our species. 



Fam. 62. Oxalidaceae. 2 : 430. 



Stamens as many as the petals; leaves entire. Fam. 63. Linaceae. 2: 435. 



Leaves pinnately compound. Fam. 66. Zygophyllaceae. 2 : 442. 



Filaments distinct (united in some Balsaminaceae). 



Flowers very irregular ; calyx with a spurred or saccate sepal. 



Fam. 64. Balsaminaceae. 2 : 440. 

 Flowers regular ; 



Herbaceous plants with pinnately divided leaves. Fam. 65. LIMNANTHACEAE. 2 : 441. 



Our species trees or shrubs with compound leaves, often punctate ; flowers dioecious or 



polygamous. 



Leaves punctate. Fam. 67. Rutaceae. 2:443. 



Leaves not punctate, but the bitter bark with oil-sacs. 



Fam. 68. Simaroubaceae. 2 : 445. 

 Flowers very irregular; petals 3; stamens usually 8; ours low herbs. 



Fam. 69. Polygalaceae. 2 : 446. 



Flowers regular, often apetalous, small, monoecious or dioecious ; carpels mostly 3 ; herbs or 



low shrubs, mostly with milky juice. Fam. 70. Euphorbiaceae. 2 : 452. 



Stamen only i ; perianth none ; styles 2 ; small aquatic or rarely terrestrial plants with opposite 



entire leaves. Fam. 71. Callitrichaceae. 2 : 477. 



$t Ovules pendulous, with the raphe away from the axis of the ovary, or erect or ascending. 



Order 17. SAPINDALES. 

 Petals none (or 3 in Empetrum) ; flowers monoecious or dioecious; leaves evergreen. 



Stamens mostly 3 ; low heath-like shrubs. Fam. 72. Empetraceae. 2 : 478. 



Stamens 4-7 ; our species an herb with broad leaves and spiked flowers. 



Fam. 73. Buxaceae. 2 : 480. 

 Petals present ; leaves deciduous, except in Cyrillaceae and some Ilicaceae. 



Ovary i -celled (in ours) ; fruit a small drupe. Fam. 74. Anacardiaceae. 2 : 480. 



Ovary 2-several-celled. 



Leaves simple, pinnately veined. 

 Seeds not arilled. 



Fruit dry ; flowers racemed, perfect. Fam. 75. Cyrillaceae. 2:485. 



Fruit a small drupe ; flowers not racemed, mostly polygamo-dioecious ; ovules pedulous. 



Fam. 76. Ilicaceae. 2 : 486. 



Seeds arilled ; ovules erect ; capsule fleshy. Fam. 77. Celastraceae. 2 : 490. 



Leaves simple and palmately veined, or compound. 

 Leaves opposite. 



Fruit a bladdery 3-lobed capsule. Fam. 78. Staphyleaceae. 2 : 493. 



Fruit of 2 winged samaras. Fam. 79. Aceraceae. 2 : 494. 



Fruit a leathery capsule ; flowers irregular ; leaves digitately compound. 



Fam. 80. Aesculaceae. 2 : 498. 

 Leaves alternate; fruit various. Fam. 81. Sapindaceae. 2: 500. 



ft Stamens as many as the sepals and alternate with them, opposite the petals when 

 these are present ; ovules erect. 



Order 18. RHAMNALES. 

 Shrubs, small trees, or vines; petals 4 or 5, or none; fruit a drupe or capsule. 



Fam. 82. Rhamnaceae. 2:501. 

 Vines, climbing by tendrils, rarely shrubs ; petals caducous ; fruit a berry. 



Fam. 83. Vitaceae. 2 : 505. 



