974 HYDROLEACEAE 



pedicelled : lobes 5, narrow. Corolla often blue, funnelform or salverform : lobes 5, broad, 

 imbricated. Stamens 5, included or nearly so : filaments irregularly adnate to the corolla- 

 tube. Ovary 1-celled or sometimes imperfectly 2-celled. Styles distinct. Ovules numer- 

 ous on each placenta. Capsule subglobose to oblong, 2-valved. Seeds very small, rugose. 

 The plants flower mainly in the spring. 



Leaves decurrent on the stem. 1. M. Jamaicense. 



Leaves not decurrent on the stem. 



Stem-leaves with sessile more or less manifestly clasping bases. 



Calyx-manifestly pedicelled : capsule about % as long as the calyx. 2. M. macranthum. 



Calyx sessile or nearly so : capsule more than % as long as the calyx. 



Calyx-lobes linear-spatulate : capsules oblong, shorter than the calyx-lobes. 3. M. undulatum. 

 Calyx-lobes narrowly linear : capsules cylindric, about as long as the calyx- 

 lobes. 4. M. stenocarpum. 

 Stem-leaves nearly sessile, often narrowed to the base, lower ones often mani- 

 festly petioled. 

 Corolla narrowly funnelform, much longer than the calyx. 



Capsule slightly shorter than the calyx-lobes : corolla about 9 mm. long. 5. M. hispidum. 

 Capsule slightly over % as long as the calyx-lobes : corolla about 10 mm. 



long. 6. M. tenue. 



Corolla short-funnelform, barely surpassing the calyx, or only slightly longer. 



Annual plants : capsule j% as long as the calyx : seeds pitted in rows. 7. M. angustifolium. 



Perennial plants : capsule about y>, as long as the calyx : seeds smooth. 8. M. origantfolium. 



1. Marilaunidium Jamaicense (L. ) Kuntze. Annual, pubescent. Stems branched 

 at the base ; branches spreading or prostrate, 1-4 dm. long : leaf-blades spatulate, often 

 broadly so, 1-5 cm. long, each tapering into a petiole-like base decurrent on the stem as a 

 wing : pedicel stout, 1-5 mm. long : calyx hirsute ; lobes narrowly linear or linear-spatu- 

 late, 6-8 mm. long, acute, ciliate : corolla white or purple, about as long as the calyx-lobes : 

 capsules narrowly oblong, 8-10 mm. long. [Nama Jamaicense L.] 



In moist soil, Florida and Texas. Also in the West Indies and Mexico. 



2. Marilaunidium macrdnthum ( Choisy ) Kuntze. Annual, hirsute. Stems branched 

 at the base; branches spreading or prosjtrate, 0.5-3 dm. long: leaves numerous; blades 

 spatulate to oblong-spatulate, 1-4 cm. long, obtuse or acutish : pedicels 4-10 mm. long : 

 calyx bristly ; lobes linear-spatulate, 8-10 mm. long, acute, ciliate : corolla about twice as 

 long as the calyx : capsules oblong, about as long as the calyx. [Nama undulatum var. 

 macranthum Choisy.] 



On plains and prairies, Texas and Mexico. 



3. Marilaunidium undulatum (H.B.K. ) Kuntze. Annual, hirsute. Stems be- 

 coming diffusely branched, prostrate, 1-3 dm. long : leaves variable ; lower ones with spatu- 

 late short-petioled blades ; upper sessile, oblong, all varying from 1-3 cm. long, often 

 crowded : pedicels solitary or several together, 1-2 mm. long : calyx bristly ; lobes linear- 

 spatulate, 6-10 mm. long : corolla funnelform, slightly surpassing the calyx : capsules ob- 

 long, shorter than the calyx, granular. [Nama undulatum H.B.K.] 



On plains and prairies, southern Texas and Mexico. 



4. Marilaunidium stenocarpum (A. Gray) Kuntze. Annual, hirsute. Stems more 

 or less diffusely branched ; branches spreading or prostrate, 1-3 dm. long : leaf-blades 

 spatulate to oblong, 1-2 cm. long, blunt, crisped : pedicels very short or none : calyx 

 bristly ; lobes narrowly linear, 7-9 mm. long, keeled : corolla about 8 mm. long : capsules 

 cylindric, shorter than the calyx. [Nama stenocarpum A. Gray.] 



On plains and prairies, Texas and Mexico to Arizona. 



5. Marilaunidium hispidum (A. Gray) Kuntze. Annual, hispid or hirsute. Stems 

 branched at the base ; branches spreading or prostrate, 0.5-2 dm. long : leaf-blades spatu- 

 late or linear-spatulate, 1-4 cm. long, obtuse, the lower short-petioled ; upper sessile : pedi- 

 cels 1-2 mm. long : calyx bristly ; lobes narrowly linear, 4-6 mm. long, often slightly 

 broadened upward : corolla about 8 mm. long ; tube surpassing the calyx : capsules nar- 

 rowly oblong, shorter than the calyx, wrinkled. [Nama hispidum A. Gray.] 



On prairies, Texas to Arizona. 



6. Marilaunidium tenue Small. 1 Annual, hirsute. Stems erect, 1-1.5 dm. tall, 

 simple below, dichotomous above, wiry : leaves opposite ; blades linear or slightly broad- 

 ened upward, 1.5-3 cm. long, sessile : pedicels slender, 1-3 mm. long : calyx bristly ; 

 lobes linear-filiform, 4-5 mm. long, erect, acute : corolla purplish, 5-6 mm. long, much 



1 Marilaunidium stenophyllum (A. Gray) Kuntze, a shrubby plant with densely hispid 

 foliage, corolla longer than the calyx and capsule about \ as long as the calyx-lobes, may 

 occur within our range. It was first found in Coahuila, Mexico, and later on the Texas 

 side of the Rio Grande. 



