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base, while most other Gerania have them united for about two-thirds or more of their length.

In the prairies about Wolf creek, in an elevation of between 6,000 and 7,000 feet, the smallest of a tribe of cactaceæ was discovered, numerous species of which were found in the course of the journey south and south-east: several others have also been discovered in Texas. I mean those dwarfish Cerei, some of which have been described with the South American genus Echinopsis, or have been referred alternately to Cereus or Echinocactus, and which I propose to distinguish from all these under the name of Echinocereus,[1] indicating their intermediate position between Cereus and Echinocactus: they approach more closely to Cereus, in which genus they, as well as the genus Echinopsis, should perhaps be included as sub-genera.

The species mentioned above is distinguished from all others known to me by its yellowish green flowers, the others having crimson or purple flowers. I have named it, therefore, Echinocereus viridiflorus.[2]

A careful examination of the seeds of numerous cactaceae, has indicated to me two principal divisions in that family: 1. Cotyledons, more or less distinct, directed with their edges to the edge, (or towards the umbilicus,) and with their faces to the flattened side of the seed; when curved, accumbent. 2. Cotyledons, mostly very distinct, foliaceous, direct with their edges to the faces, and with their faces to the edges of the seed, (or towards the umbilicus;) when curved, incumbent, and often circular or spiral.

The first class comprises Mammillaria, with a straight embryo; and


  1. Echinocereus, n. gen. Perigonii tubus ultra germen productus, abbreviatus. Sepala exteriora s. tubi subulata, in axillis tomentosis setas s. aculeos gerentes. Sepala interiora subpetaloidea et petala longiora pluriserialia corollam breviter infundibuliformem s. sub-campanulatam aemulantia. Stamina numerosissima tubo adnata, limbo breviora s. eum subaequantia. Stylus stamina vix superans. Stigma multiradiatum. Bacca pulvilligera setosa s. aculeata, perigonio coronata. Seminum testa dura tuberculata nigra. Embryo vix curvatus cotyledonibus brevibus contrariis. Globose, or mostly ovate; simple, or mostly branching from the base or cespitose; tubercles, forming few or mostly a great many ribs; bunches of short or long spines, distant or approximate, often very crowded; vertex never woolly; flowers lateral, produced from last year’s growth, opening only in sunshine, but for two or three days in succession; closed at night, or in dark weather.
  2. Echinocereus viridiflorus, n. sp. ovato-globusus, humilis, sub-13-costatus; areolis lanceolatis, approximatis, junioribus villosis; aculeis 16-18 rectis, radiantibus, lateralibus longioribus fuscis, reliquis albidis, centrali nullo s. elongato robusto, apice fusco; floribus lateralibus; tubo pulvillis 25-30 albo-tomentosis setas albas 5-10 gerentibus stipato; sepalis interioribus lineari-oblongis sub-10; petalis 12-15 lineari-oblongis, obtusis; baccis ellipticis virescentibus, seminibus parvis tuberculatis. Prairies on Wolf creek, flowers in June; Santa Fe, flowers in May, (Fendler.) Body 1 to 11/2 inch high, oval; spines 1 or 11/2 to 3 lines long; central spine when present 6 to 7 lines long; flower 1 inch long and wide, outside green brown, inside yellowish green; petals only 2 lines wide, being about 5 lines long.