CXL. ORCHIDA(JJ<:/E. 629 



Coiispeclun of the Gimcra. 



, pctiomte. Hydrocharis. 1 



< short and verticillalc, sessile. Flowers axillury, soliliiry IJdoia. 1 



Leaves ( lonjj, linear, radical. Flowers elevated on loii« swipes VatUmieria. 3 



1. HYDllOCU AlUS. 



Crr. vSiop, water, ^aipdi, to rejoice ; ns water is its own element. 



Flowers d 9 . — Spathe 2-leaved ; calyx o-parted ; corolla of 3 pe- 

 tals ; styles 3, abortive in the d" : sta. 10 — 12, infertile in 9 ; stig. 

 6 — 8, bifid, with several barren filaments and 3 nectariferous glands ; 

 caps, inferior, G-celled, 00-seeded. — Floating aquatics. 



H. sroNGiOsA. Bosc. (H. cordifblia. Null.) Progblt. 



Lis. roundish-cordate; c^ Jls. on long peduncles, '^ on short ones; anih. 

 linear; .<;//>. (' — 7, 2-parted nearly to the base; segments lanceolate-subulate. — % 

 Braddock's bay, L. Ontario, Sartircll. Stems jointed, producing offsets from 

 which new plants arise. Root .somewhat librous. Leaves petiolate, 5-veined, 

 purplish beneath. (^ peduncles about 3' long. Sepals oval, green. Q pedun- 

 cles 1 — IJ' long, thick. Ovaiy oblong. Seeds hirsute. Petals white. Aug. 



2. UDORA. Nutt. 



Gr. vScop, water ; from its aciuatic habits. 



Flowers d" 9; spathe bifid ; spadix 1 -flowered, d Stamens 9, 3 of 

 them interior. 9 Tube of the perianth very long ; abortive filaments 

 3 ; capsule ventricose, 3-seeded. — Creeping. Lvs. verticitlate. 



U. Canadensis. Nutt. (Elodea. Michx. Sepicula verticillata. Mnhl.) 

 Ditch Moss.— Lvs. verticillate, in 3s and 4s, lanceolate, oblong or linear, 

 serrulate ; tube of the perianth fililbrm. — Resembling a coarse moss, in still 

 waters. Stem fililbrm, diffusely dichotomous, very leafy, submersed. Leaves 

 3— G" by (less than) 1", thin and diaphanous, sessile, obtuse. Flowers axillary, 

 solitary, minute, of a dingy white, the slender, hair-like tube 2^3' long (4—6' 

 according to Nidtall), the lower part (pedicell) 2-margined, Stigmas recurved 

 between the segments, crested with glandular hairs. Aug. 



3. VALLISNERIA. 



In honor of Anthony Vallisncr, a French botanist. 



Flowers J" 9; spathe ovate, 2— 4-parted. d" Spadix covered with 

 minute flowers; corolla 0. 9 Spathe bifid, 1 -flowered; perianth 

 elongated ; sepals linear ; stigmas 3, ovate, bifid ; capsule 1 -celled, 

 many-seeded. — % Submersed. Lvs. all radical. Scape spiral, very long. 



V. Americana. Michx. Tape Grass. 



Lvs. linear, obtuse, serrulate at the end, tapering at the base, floating ; 

 peduncle of the fertile fimoer long, of the sterile short, erect. — A curious plant, iii 

 slow moving or stagnant waters, U. S. Leaves linear, 1 — 2f long, about ^' 

 wide, the edges thinner than the middle. Scapes several, of the sterile plants 

 short, of the fertile plants very tortuous, 2— 4f long when extended, thread-like, 

 thickened at top, bearing each a single, white flower at or near the surface. 

 Sepals and petals crowning the (I') long, narrow, incurved ovary, which is 

 half concealed in the spathe. July, Aug. 



Order CXL. ORCHIDACE^.— Orchids. 



Herbs perennial, often acaulescent, with fleshy corms, or tuberous, fasciculated roots. 



Lvs. simple, parallel-veined, entire. F/s. in terminal or radical racemes, spikes or panicles, rarely solitary 



F/s.— Ver>' irregular, with an adherent, rineent perianth of 6 parts. 



Ca/.— i^epals 3, usually colored, odd one uppermost by the twisting of the ovary. 



Co?-.— Petals 3, u.sually colored, odd one lowest by the twisting of the ovary. 



Lip. (labeUum, or lowest pet;il.) diverse in form, often lobed, frequently spurred at base. 



Sta. 3, united into a central column, the 2 lateral ones generally abortive, and the central one perfect • 



more rarely the central abortive ;md lateral perfect. 

 Anth. 1. 4 or 8-celled, persistent or deriduous, often operculate. 

 Pol. either po\ydery, or cohering in waxy masses (polUnia), which are either constantly adhering to a 



gland, or becominR loose in their cells. 



